/* Subroutine */ int slaqr0_(logical *wantt, logical *wantz, integer *n,
integer *ilo, integer *ihi, real *h__, integer *ldh, real *wr, real *
wi, integer *iloz, integer *ihiz, real *z__, integer *ldz, real *work,
integer *lwork, integer *info)
{
/* System generated locals */
integer h_dim1, h_offset, z_dim1, z_offset, i__1, i__2, i__3, i__4, i__5;
real r__1, r__2, r__3, r__4;
/* Local variables */
integer i__, k;
real aa, bb, cc, dd;
integer ld;
real cs;
integer nh, it, ks, kt;
real sn;
integer ku, kv, ls, ns;
real ss;
integer nw, inf, kdu, nho, nve, kwh, nsr, nwr, kwv, ndec, ndfl, kbot,
nmin;
real swap;
integer ktop;
real zdum[1] /* was [1][1] */;
integer kacc22, itmax, nsmax, nwmax, kwtop;
extern /* Subroutine */ int slanv2_(real *, real *, real *, real *, real *
, real *, real *, real *, real *, real *), slaqr3_(logical *,
logical *, integer *, integer *, integer *, integer *, real *,
integer *, integer *, integer *, real *, integer *, integer *,
integer *, real *, real *, real *, integer *, integer *, real *,
integer *, integer *, real *, integer *, real *, integer *),
slaqr4_(logical *, logical *, integer *, integer *, integer *,
real *, integer *, real *, real *, integer *, integer *, real *,
integer *, real *, integer *, integer *), slaqr5_(logical *,
logical *, integer *, integer *, integer *, integer *, integer *,
real *, real *, real *, integer *, integer *, integer *, real *,
integer *, real *, integer *, real *, integer *, integer *, real *
, integer *, integer *, real *, integer *);
integer nibble;
extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
integer *, integer *);
char jbcmpz[2];
extern /* Subroutine */ int slahqr_(logical *, logical *, integer *,
integer *, integer *, real *, integer *, real *, real *, integer *
, integer *, real *, integer *, integer *), slacpy_(char *,
integer *, integer *, real *, integer *, real *, integer *);
integer nwupbd;
logical sorted;
integer lwkopt;
/* -- LAPACK auxiliary routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* SLAQR0 computes the eigenvalues of a Hessenberg matrix H */
/* and, optionally, the matrices T and Z from the Schur decomposition */
/* H = Z T Z**T, where T is an upper quasi-triangular matrix (the */
/* Schur form), and Z is the orthogonal matrix of Schur vectors. */
/* Optionally Z may be postmultiplied into an input orthogonal */
/* matrix Q so that this routine can give the Schur factorization */
/* of a matrix A which has been reduced to the Hessenberg form H */
/* by the orthogonal matrix Q: A = Q*H*Q**T = (QZ)*T*(QZ)**T. */
/* Arguments */
/* ========= */
/* WANTT (input) LOGICAL */
/* = .TRUE. : the full Schur form T is required; */
/* = .FALSE.: only eigenvalues are required. */
/* WANTZ (input) LOGICAL */
/* = .TRUE. : the matrix of Schur vectors Z is required; */
/* = .FALSE.: Schur vectors are not required. */
/* N (input) INTEGER */
/* The order of the matrix H. N .GE. 0. */
/* ILO (input) INTEGER */
/* IHI (input) INTEGER */
/* It is assumed that H is already upper triangular in rows */
/* and columns 1:ILO-1 and IHI+1:N and, if ILO.GT.1, */
/* H(ILO,ILO-1) is zero. ILO and IHI are normally set by a */
/* previous call to SGEBAL, and then passed to SGEHRD when the */
/* matrix output by SGEBAL is reduced to Hessenberg form. */
/* Otherwise, ILO and IHI should be set to 1 and N, */
/* respectively. If N.GT.0, then 1.LE.ILO.LE.IHI.LE.N. */
/* If N = 0, then ILO = 1 and IHI = 0. */
/* H (input/output) REAL array, dimension (LDH,N) */
/* On entry, the upper Hessenberg matrix H. */
/* On exit, if INFO = 0 and WANTT is .TRUE., then H contains */
/* the upper quasi-triangular matrix T from the Schur */
/* decomposition (the Schur form); 2-by-2 diagonal blocks */
/* (corresponding to complex conjugate pairs of eigenvalues) */
/* are returned in standard form, with H(i,i) = H(i+1,i+1) */
/* and H(i+1,i)*H(i,i+1).LT.0. If INFO = 0 and WANTT is */
/* .FALSE., then the contents of H are unspecified on exit. */
/* (The output value of H when INFO.GT.0 is given under the */
/* description of INFO below.) */
/* This subroutine may explicitly set H(i,j) = 0 for i.GT.j and */
/* j = 1, 2, ... ILO-1 or j = IHI+1, IHI+2, ... N. */
/* LDH (input) INTEGER */
/* The leading dimension of the array H. LDH .GE. max(1,N). */
/* WR (output) REAL array, dimension (IHI) */
/* WI (output) REAL array, dimension (IHI) */
/* The real and imaginary parts, respectively, of the computed */
/* eigenvalues of H(ILO:IHI,ILO:IHI) are stored in WR(ILO:IHI) */
/* and WI(ILO:IHI). If two eigenvalues are computed as a */
/* complex conjugate pair, they are stored in consecutive */
/* elements of WR and WI, say the i-th and (i+1)th, with */
/* WI(i) .GT. 0 and WI(i+1) .LT. 0. If WANTT is .TRUE., then */
/* the eigenvalues are stored in the same order as on the */
/* diagonal of the Schur form returned in H, with */
/* WR(i) = H(i,i) and, if H(i:i+1,i:i+1) is a 2-by-2 diagonal */
/* block, WI(i) = sqrt(-H(i+1,i)*H(i,i+1)) and */
/* WI(i+1) = -WI(i). */
/* ILOZ (input) INTEGER */
/* IHIZ (input) INTEGER */
/* Specify the rows of Z to which transformations must be */
/* applied if WANTZ is .TRUE.. */
/* 1 .LE. ILOZ .LE. ILO; IHI .LE. IHIZ .LE. N. */
/* Z (input/output) REAL array, dimension (LDZ,IHI) */
/* If WANTZ is .FALSE., then Z is not referenced. */
/* If WANTZ is .TRUE., then Z(ILO:IHI,ILOZ:IHIZ) is */
/* replaced by Z(ILO:IHI,ILOZ:IHIZ)*U where U is the */
/* orthogonal Schur factor of H(ILO:IHI,ILO:IHI). */
/* (The output value of Z when INFO.GT.0 is given under */
/* the description of INFO below.) */
/* LDZ (input) INTEGER */
/* The leading dimension of the array Z. if WANTZ is .TRUE. */
/* then LDZ.GE.MAX(1,IHIZ). Otherwize, LDZ.GE.1. */
/* WORK (workspace/output) REAL array, dimension LWORK */
/* On exit, if LWORK = -1, WORK(1) returns an estimate of */
/* the optimal value for LWORK. */
/* LWORK (input) INTEGER */
/* The dimension of the array WORK. LWORK .GE. max(1,N) */
/* is sufficient, but LWORK typically as large as 6*N may */
/* be required for optimal performance. A workspace query */
/* to determine the optimal workspace size is recommended. */
/* If LWORK = -1, then SLAQR0 does a workspace query. */
/* In this case, SLAQR0 checks the input parameters and */
/* estimates the optimal workspace size for the given */
/* values of N, ILO and IHI. The estimate is returned */
/* in WORK(1). No error message related to LWORK is */
/* issued by XERBLA. Neither H nor Z are accessed. */
/* INFO (output) INTEGER */
/* = 0: successful exit */
/* .GT. 0: if INFO = i, SLAQR0 failed to compute all of */
/* the eigenvalues. Elements 1:ilo-1 and i+1:n of WR */
/* and WI contain those eigenvalues which have been */
/* successfully computed. (Failures are rare.) */
/* If INFO .GT. 0 and WANT is .FALSE., then on exit, */
/* the remaining unconverged eigenvalues are the eigen- */
/* values of the upper Hessenberg matrix rows and */
/* columns ILO through INFO of the final, output */
/* value of H. */
/* If INFO .GT. 0 and WANTT is .TRUE., then on exit */
/* (*) (initial value of H)*U = U*(final value of H) */
/* where U is an orthogonal matrix. The final */
/* value of H is upper Hessenberg and quasi-triangular */
/* in rows and columns INFO+1 through IHI. */
/* If INFO .GT. 0 and WANTZ is .TRUE., then on exit */
/* (final value of Z(ILO:IHI,ILOZ:IHIZ) */
/* = (initial value of Z(ILO:IHI,ILOZ:IHIZ)*U */
/* where U is the orthogonal matrix in (*) (regard- */
/* less of the value of WANTT.) */
/* If INFO .GT. 0 and WANTZ is .FALSE., then Z is not */
/* accessed. */
/* ================================================================ */
/* Based on contributions by */
/* Karen Braman and Ralph Byers, Department of Mathematics, */
/* University of Kansas, USA */
/* ================================================================ */
/* References: */
/* K. Braman, R. Byers and R. Mathias, The Multi-Shift QR */
/* Algorithm Part I: Maintaining Well Focused Shifts, and Level 3 */
/* Performance, SIAM Journal of Matrix Analysis, volume 23, pages */
/* 929--947, 2002. */
/* K. Braman, R. Byers and R. Mathias, The Multi-Shift QR */
/* Algorithm Part II: Aggressive Early Deflation, SIAM Journal */
/* of Matrix Analysis, volume 23, pages 948--973, 2002. */
/* ================================================================ */
/* .. Parameters .. */
/* ==== Matrices of order NTINY or smaller must be processed by */
/* . SLAHQR because of insufficient subdiagonal scratch space. */
/* . (This is a hard limit.) ==== */
/* ==== Exceptional deflation windows: try to cure rare */
/* . slow convergence by varying the size of the */
/* . deflation window after KEXNW iterations. ==== */
/* ==== Exceptional shifts: try to cure rare slow convergence */
/* . with ad-hoc exceptional shifts every KEXSH iterations. */
/* . ==== */
/* ==== The constants WILK1 and WILK2 are used to form the */
/* . exceptional shifts. ==== */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. Local Arrays .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Parameter adjustments */
h_dim1 = *ldh;
h_offset = 1 + h_dim1;
h__ -= h_offset;
--wr;
--wi;
z_dim1 = *ldz;
z_offset = 1 + z_dim1;
z__ -= z_offset;
--work;
/* Function Body */
*info = 0;
/* ==== Quick return for N = 0: nothing to do. ==== */
if (*n == 0) {
work[1] = 1.f;
return 0;
}
if (*n <= 11) {
/* ==== Tiny matrices must use SLAHQR. ==== */
lwkopt = 1;
if (*lwork != -1) {
slahqr_(wantt, wantz, n, ilo, ihi, &h__[h_offset], ldh, &wr[1], &
wi[1], iloz, ihiz, &z__[z_offset], ldz, info);
}
} else {
/* ==== Use small bulge multi-shift QR with aggressive early */
/* . deflation on larger-than-tiny matrices. ==== */
/* ==== Hope for the best. ==== */
*info = 0;
/* ==== Set up job flags for ILAENV. ==== */
if (*wantt) {
*(unsigned char *)jbcmpz = 'S';
} else {
*(unsigned char *)jbcmpz = 'E';
}
if (*wantz) {
*(unsigned char *)&jbcmpz[1] = 'V';
} else {
*(unsigned char *)&jbcmpz[1] = 'N';
}
/* ==== NWR = recommended deflation window size. At this */
/* . point, N .GT. NTINY = 11, so there is enough */
/* . subdiagonal workspace for NWR.GE.2 as required. */
/* . (In fact, there is enough subdiagonal space for */
/* . NWR.GE.3.) ==== */
nwr = ilaenv_(&c__13, "SLAQR0", jbcmpz, n, ilo, ihi, lwork);
nwr = max(2,nwr);
/* Computing MIN */
i__1 = *ihi - *ilo + 1, i__2 = (*n - 1) / 3, i__1 = min(i__1,i__2);
nwr = min(i__1,nwr);
/* ==== NSR = recommended number of simultaneous shifts. */
/* . At this point N .GT. NTINY = 11, so there is at */
/* . enough subdiagonal workspace for NSR to be even */
/* . and greater than or equal to two as required. ==== */
nsr = ilaenv_(&c__15, "SLAQR0", jbcmpz, n, ilo, ihi, lwork);
/* Computing MIN */
i__1 = nsr, i__2 = (*n + 6) / 9, i__1 = min(i__1,i__2), i__2 = *ihi -
*ilo;
nsr = min(i__1,i__2);
/* Computing MAX */
i__1 = 2, i__2 = nsr - nsr % 2;
nsr = max(i__1,i__2);
/* ==== Estimate optimal workspace ==== */
/* ==== Workspace query call to SLAQR3 ==== */
i__1 = nwr + 1;
slaqr3_(wantt, wantz, n, ilo, ihi, &i__1, &h__[h_offset], ldh, iloz,
ihiz, &z__[z_offset], ldz, &ls, &ld, &wr[1], &wi[1], &h__[
h_offset], ldh, n, &h__[h_offset], ldh, n, &h__[h_offset],
ldh, &work[1], &c_n1);
/* ==== Optimal workspace = MAX(SLAQR5, SLAQR3) ==== */
/* Computing MAX */
i__1 = nsr * 3 / 2, i__2 = (integer) work[1];
lwkopt = max(i__1,i__2);
/* ==== Quick return in case of workspace query. ==== */
if (*lwork == -1) {
work[1] = (real) lwkopt;
return 0;
}
/* ==== SLAHQR/SLAQR0 crossover point ==== */
nmin = ilaenv_(&c__12, "SLAQR0", jbcmpz, n, ilo, ihi, lwork);
nmin = max(11,nmin);
/* ==== Nibble crossover point ==== */
nibble = ilaenv_(&c__14, "SLAQR0", jbcmpz, n, ilo, ihi, lwork);
nibble = max(0,nibble);
/* ==== Accumulate reflections during ttswp? Use block */
/* . 2-by-2 structure during matrix-matrix multiply? ==== */
kacc22 = ilaenv_(&c__16, "SLAQR0", jbcmpz, n, ilo, ihi, lwork);
kacc22 = max(0,kacc22);
kacc22 = min(2,kacc22);
/* ==== NWMAX = the largest possible deflation window for */
/* . which there is sufficient workspace. ==== */
/* Computing MIN */
i__1 = (*n - 1) / 3, i__2 = *lwork / 2;
nwmax = min(i__1,i__2);
nw = nwmax;
/* ==== NSMAX = the Largest number of simultaneous shifts */
/* . for which there is sufficient workspace. ==== */
/* Computing MIN */
i__1 = (*n + 6) / 9, i__2 = (*lwork << 1) / 3;
nsmax = min(i__1,i__2);
nsmax -= nsmax % 2;
/* ==== NDFL: an iteration count restarted at deflation. ==== */
ndfl = 1;
/* ==== ITMAX = iteration limit ==== */
/* Computing MAX */
i__1 = 10, i__2 = *ihi - *ilo + 1;
itmax = max(i__1,i__2) * 30;
/* ==== Last row and column in the active block ==== */
kbot = *ihi;
/* ==== Main Loop ==== */
i__1 = itmax;
for (it = 1; it <= i__1; ++it) {
/* ==== Done when KBOT falls below ILO ==== */
if (kbot < *ilo) {
goto L90;
}
/* ==== Locate active block ==== */
i__2 = *ilo + 1;
for (k = kbot; k >= i__2; --k) {
if (h__[k + (k - 1) * h_dim1] == 0.f) {
goto L20;
}
/* L10: */
}
k = *ilo;
L20:
ktop = k;
/* ==== Select deflation window size: */
/* . Typical Case: */
/* . If possible and advisable, nibble the entire */
/* . active block. If not, use size MIN(NWR,NWMAX) */
/* . or MIN(NWR+1,NWMAX) depending upon which has */
/* . the smaller corresponding subdiagonal entry */
/* . (a heuristic). */
/* . */
/* . Exceptional Case: */
/* . If there have been no deflations in KEXNW or */
/* . more iterations, then vary the deflation window */
/* . size. At first, because, larger windows are, */
/* . in general, more powerful than smaller ones, */
/* . rapidly increase the window to the maximum possible. */
/* . Then, gradually reduce the window size. ==== */
nh = kbot - ktop + 1;
nwupbd = min(nh,nwmax);
if (ndfl < 5) {
nw = min(nwupbd,nwr);
} else {
/* Computing MIN */
i__2 = nwupbd, i__3 = nw << 1;
nw = min(i__2,i__3);
}
if (nw < nwmax) {
if (nw >= nh - 1) {
nw = nh;
} else {
kwtop = kbot - nw + 1;
if ((r__1 = h__[kwtop + (kwtop - 1) * h_dim1], dabs(r__1))
> (r__2 = h__[kwtop - 1 + (kwtop - 2) * h_dim1],
dabs(r__2))) {
++nw;
}
}
}
if (ndfl < 5) {
ndec = -1;
} else if (ndec >= 0 || nw >= nwupbd) {
++ndec;
if (nw - ndec < 2) {
ndec = 0;
}
nw -= ndec;
}
/* ==== Aggressive early deflation: */
/* . split workspace under the subdiagonal into */
/* . - an nw-by-nw work array V in the lower */
/* . left-hand-corner, */
/* . - an NW-by-at-least-NW-but-more-is-better */
/* . (NW-by-NHO) horizontal work array along */
/* . the bottom edge, */
/* . - an at-least-NW-but-more-is-better (NHV-by-NW) */
/* . vertical work array along the left-hand-edge. */
/* . ==== */
kv = *n - nw + 1;
kt = nw + 1;
nho = *n - nw - 1 - kt + 1;
kwv = nw + 2;
nve = *n - nw - kwv + 1;
/* ==== Aggressive early deflation ==== */
slaqr3_(wantt, wantz, n, &ktop, &kbot, &nw, &h__[h_offset], ldh,
iloz, ihiz, &z__[z_offset], ldz, &ls, &ld, &wr[1], &wi[1],
&h__[kv + h_dim1], ldh, &nho, &h__[kv + kt * h_dim1],
ldh, &nve, &h__[kwv + h_dim1], ldh, &work[1], lwork);
/* ==== Adjust KBOT accounting for new deflations. ==== */
kbot -= ld;
/* ==== KS points to the shifts. ==== */
ks = kbot - ls + 1;
/* ==== Skip an expensive QR sweep if there is a (partly */
/* . heuristic) reason to expect that many eigenvalues */
/* . will deflate without it. Here, the QR sweep is */
/* . skipped if many eigenvalues have just been deflated */
/* . or if the remaining active block is small. */
if (ld == 0 || ld * 100 <= nw * nibble && kbot - ktop + 1 > min(
nmin,nwmax)) {
/* ==== NS = nominal number of simultaneous shifts. */
/* . This may be lowered (slightly) if SLAQR3 */
/* . did not provide that many shifts. ==== */
/* Computing MIN */
/* Computing MAX */
i__4 = 2, i__5 = kbot - ktop;
i__2 = min(nsmax,nsr), i__3 = max(i__4,i__5);
ns = min(i__2,i__3);
ns -= ns % 2;
/* ==== If there have been no deflations */
/* . in a multiple of KEXSH iterations, */
/* . then try exceptional shifts. */
/* . Otherwise use shifts provided by */
/* . SLAQR3 above or from the eigenvalues */
/* . of a trailing principal submatrix. ==== */
if (ndfl % 6 == 0) {
ks = kbot - ns + 1;
/* Computing MAX */
i__3 = ks + 1, i__4 = ktop + 2;
i__2 = max(i__3,i__4);
for (i__ = kbot; i__ >= i__2; i__ += -2) {
ss = (r__1 = h__[i__ + (i__ - 1) * h_dim1], dabs(r__1)
) + (r__2 = h__[i__ - 1 + (i__ - 2) * h_dim1],
dabs(r__2));
aa = ss * .75f + h__[i__ + i__ * h_dim1];
bb = ss;
cc = ss * -.4375f;
dd = aa;
slanv2_(&aa, &bb, &cc, &dd, &wr[i__ - 1], &wi[i__ - 1]
, &wr[i__], &wi[i__], &cs, &sn);
/* L30: */
}
if (ks == ktop) {
wr[ks + 1] = h__[ks + 1 + (ks + 1) * h_dim1];
wi[ks + 1] = 0.f;
wr[ks] = wr[ks + 1];
wi[ks] = wi[ks + 1];
}
} else {
/* ==== Got NS/2 or fewer shifts? Use SLAQR4 or */
/* . SLAHQR on a trailing principal submatrix to */
/* . get more. (Since NS.LE.NSMAX.LE.(N+6)/9, */
/* . there is enough space below the subdiagonal */
/* . to fit an NS-by-NS scratch array.) ==== */
if (kbot - ks + 1 <= ns / 2) {
ks = kbot - ns + 1;
kt = *n - ns + 1;
slacpy_("A", &ns, &ns, &h__[ks + ks * h_dim1], ldh, &
h__[kt + h_dim1], ldh);
if (ns > nmin) {
slaqr4_(&c_false, &c_false, &ns, &c__1, &ns, &h__[
kt + h_dim1], ldh, &wr[ks], &wi[ks], &
c__1, &c__1, zdum, &c__1, &work[1], lwork,
&inf);
} else {
slahqr_(&c_false, &c_false, &ns, &c__1, &ns, &h__[
kt + h_dim1], ldh, &wr[ks], &wi[ks], &
c__1, &c__1, zdum, &c__1, &inf);
}
ks += inf;
/* ==== In case of a rare QR failure use */
/* . eigenvalues of the trailing 2-by-2 */
/* . principal submatrix. ==== */
if (ks >= kbot) {
aa = h__[kbot - 1 + (kbot - 1) * h_dim1];
cc = h__[kbot + (kbot - 1) * h_dim1];
bb = h__[kbot - 1 + kbot * h_dim1];
dd = h__[kbot + kbot * h_dim1];
slanv2_(&aa, &bb, &cc, &dd, &wr[kbot - 1], &wi[
kbot - 1], &wr[kbot], &wi[kbot], &cs, &sn)
;
ks = kbot - 1;
}
}
if (kbot - ks + 1 > ns) {
/* ==== Sort the shifts (Helps a little) */
/* . Bubble sort keeps complex conjugate */
/* . pairs together. ==== */
sorted = FALSE_;
i__2 = ks + 1;
for (k = kbot; k >= i__2; --k) {
if (sorted) {
goto L60;
}
sorted = TRUE_;
i__3 = k - 1;
for (i__ = ks; i__ <= i__3; ++i__) {
if ((r__1 = wr[i__], dabs(r__1)) + (r__2 = wi[
i__], dabs(r__2)) < (r__3 = wr[i__ +
1], dabs(r__3)) + (r__4 = wi[i__ + 1],
dabs(r__4))) {
sorted = FALSE_;
swap = wr[i__];
wr[i__] = wr[i__ + 1];
wr[i__ + 1] = swap;
swap = wi[i__];
wi[i__] = wi[i__ + 1];
wi[i__ + 1] = swap;
}
/* L40: */
}
/* L50: */
}
L60:
;
}
/* ==== Shuffle shifts into pairs of real shifts */
/* . and pairs of complex conjugate shifts */
/* . assuming complex conjugate shifts are */
/* . already adjacent to one another. (Yes, */
/* . they are.) ==== */
i__2 = ks + 2;
for (i__ = kbot; i__ >= i__2; i__ += -2) {
if (wi[i__] != -wi[i__ - 1]) {
swap = wr[i__];
wr[i__] = wr[i__ - 1];
wr[i__ - 1] = wr[i__ - 2];
wr[i__ - 2] = swap;
swap = wi[i__];
wi[i__] = wi[i__ - 1];
wi[i__ - 1] = wi[i__ - 2];
wi[i__ - 2] = swap;
}
/* L70: */
}
}
/* ==== If there are only two shifts and both are */
/* . real, then use only one. ==== */
if (kbot - ks + 1 == 2) {
if (wi[kbot] == 0.f) {
if ((r__1 = wr[kbot] - h__[kbot + kbot * h_dim1],
dabs(r__1)) < (r__2 = wr[kbot - 1] - h__[kbot
+ kbot * h_dim1], dabs(r__2))) {
wr[kbot - 1] = wr[kbot];
} else {
wr[kbot] = wr[kbot - 1];
}
}
}
/* ==== Use up to NS of the the smallest magnatiude */
/* . shifts. If there aren't NS shifts available, */
/* . then use them all, possibly dropping one to */
/* . make the number of shifts even. ==== */
/* Computing MIN */
i__2 = ns, i__3 = kbot - ks + 1;
ns = min(i__2,i__3);
ns -= ns % 2;
ks = kbot - ns + 1;
/* ==== Small-bulge multi-shift QR sweep: */
/* . split workspace under the subdiagonal into */
/* . - a KDU-by-KDU work array U in the lower */
/* . left-hand-corner, */
/* . - a KDU-by-at-least-KDU-but-more-is-better */
/* . (KDU-by-NHo) horizontal work array WH along */
/* . the bottom edge, */
/* . - and an at-least-KDU-but-more-is-better-by-KDU */
/* . (NVE-by-KDU) vertical work WV arrow along */
/* . the left-hand-edge. ==== */
kdu = ns * 3 - 3;
ku = *n - kdu + 1;
kwh = kdu + 1;
nho = *n - kdu - 3 - (kdu + 1) + 1;
kwv = kdu + 4;
nve = *n - kdu - kwv + 1;
/* ==== Small-bulge multi-shift QR sweep ==== */
slaqr5_(wantt, wantz, &kacc22, n, &ktop, &kbot, &ns, &wr[ks],
&wi[ks], &h__[h_offset], ldh, iloz, ihiz, &z__[
z_offset], ldz, &work[1], &c__3, &h__[ku + h_dim1],
ldh, &nve, &h__[kwv + h_dim1], ldh, &nho, &h__[ku +
kwh * h_dim1], ldh);
}
/* ==== Note progress (or the lack of it). ==== */
if (ld > 0) {
ndfl = 1;
} else {
++ndfl;
}
/* ==== End of main loop ==== */
/* L80: */
}
/* ==== Iteration limit exceeded. Set INFO to show where */
/* . the problem occurred and exit. ==== */
*info = kbot;
L90:
;
}
/* ==== Return the optimal value of LWORK. ==== */
work[1] = (real) lwkopt;
/* ==== End of SLAQR0 ==== */
return 0;
} /* slaqr0_ */
/* Subroutine */
int slaqr2_(logical *wantt, logical *wantz, integer *n, integer *ktop, integer *kbot, integer *nw, real *h__, integer *ldh, integer *iloz, integer *ihiz, real *z__, integer *ldz, integer *ns, integer *nd, real *sr, real *si, real *v, integer *ldv, integer *nh, real *t, integer *ldt, integer *nv, real *wv, integer *ldwv, real * work, integer *lwork)
{
/* System generated locals */
integer h_dim1, h_offset, t_dim1, t_offset, v_dim1, v_offset, wv_dim1, wv_offset, z_dim1, z_offset, i__1, i__2, i__3, i__4;
real r__1, r__2, r__3, r__4, r__5, r__6;
/* Builtin functions */
double sqrt(doublereal);
/* Local variables */
integer i__, j, k;
real s, aa, bb, cc, dd, cs, sn;
integer jw;
real evi, evk, foo;
integer kln;
real tau, ulp;
integer lwk1, lwk2;
real beta;
integer kend, kcol, info, ifst, ilst, ltop, krow;
logical bulge;
extern /* Subroutine */
int slarf_(char *, integer *, integer *, real *, integer *, real *, real *, integer *, real *), sgemm_( char *, char *, integer *, integer *, integer *, real *, real *, integer *, real *, integer *, real *, real *, integer *);
integer infqr;
extern /* Subroutine */
int scopy_(integer *, real *, integer *, real *, integer *);
integer kwtop;
extern /* Subroutine */
int slanv2_(real *, real *, real *, real *, real * , real *, real *, real *, real *, real *), slabad_(real *, real *) ;
extern real slamch_(char *);
extern /* Subroutine */
int sgehrd_(integer *, integer *, integer *, real *, integer *, real *, real *, integer *, integer *);
real safmin;
extern /* Subroutine */
int slarfg_(integer *, real *, real *, integer *, real *);
real safmax;
extern /* Subroutine */
int slahqr_(logical *, logical *, integer *, integer *, integer *, real *, integer *, real *, real *, integer * , integer *, real *, integer *, integer *), slacpy_(char *, integer *, integer *, real *, integer *, real *, integer *), slaset_(char *, integer *, integer *, real *, real *, real *, integer *);
logical sorted;
extern /* Subroutine */
int strexc_(char *, integer *, real *, integer *, real *, integer *, integer *, integer *, real *, integer *), sormhr_(char *, char *, integer *, integer *, integer *, integer *, real *, integer *, real *, real *, integer *, real *, integer *, integer *);
real smlnum;
integer lwkopt;
/* -- LAPACK auxiliary routine (version 3.4.2) -- */
/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
/* September 2012 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* ================================================================ */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* ==== Estimate optimal workspace. ==== */
/* Parameter adjustments */
h_dim1 = *ldh;
h_offset = 1 + h_dim1;
h__ -= h_offset;
z_dim1 = *ldz;
z_offset = 1 + z_dim1;
z__ -= z_offset;
--sr;
--si;
v_dim1 = *ldv;
v_offset = 1 + v_dim1;
v -= v_offset;
t_dim1 = *ldt;
t_offset = 1 + t_dim1;
t -= t_offset;
wv_dim1 = *ldwv;
wv_offset = 1 + wv_dim1;
wv -= wv_offset;
--work;
/* Function Body */
/* Computing MIN */
i__1 = *nw;
i__2 = *kbot - *ktop + 1; // , expr subst
jw = min(i__1,i__2);
if (jw <= 2)
{
lwkopt = 1;
}
else
{
/* ==== Workspace query call to SGEHRD ==== */
i__1 = jw - 1;
sgehrd_(&jw, &c__1, &i__1, &t[t_offset], ldt, &work[1], &work[1], & c_n1, &info);
lwk1 = (integer) work[1];
/* ==== Workspace query call to SORMHR ==== */
i__1 = jw - 1;
sormhr_("R", "N", &jw, &jw, &c__1, &i__1, &t[t_offset], ldt, &work[1], &v[v_offset], ldv, &work[1], &c_n1, &info);
lwk2 = (integer) work[1];
/* ==== Optimal workspace ==== */
lwkopt = jw + max(lwk1,lwk2);
}
/* ==== Quick return in case of workspace query. ==== */
if (*lwork == -1)
{
work[1] = (real) lwkopt;
return 0;
}
/* ==== Nothing to do ... */
/* ... for an empty active block ... ==== */
*ns = 0;
*nd = 0;
work[1] = 1.f;
if (*ktop > *kbot)
{
return 0;
}
/* ... nor for an empty deflation window. ==== */
if (*nw < 1)
{
return 0;
}
/* ==== Machine constants ==== */
safmin = slamch_("SAFE MINIMUM");
safmax = 1.f / safmin;
slabad_(&safmin, &safmax);
ulp = slamch_("PRECISION");
smlnum = safmin * ((real) (*n) / ulp);
/* ==== Setup deflation window ==== */
/* Computing MIN */
i__1 = *nw;
i__2 = *kbot - *ktop + 1; // , expr subst
jw = min(i__1,i__2);
kwtop = *kbot - jw + 1;
if (kwtop == *ktop)
{
s = 0.f;
}
else
{
s = h__[kwtop + (kwtop - 1) * h_dim1];
}
if (*kbot == kwtop)
{
/* ==== 1-by-1 deflation window: not much to do ==== */
sr[kwtop] = h__[kwtop + kwtop * h_dim1];
si[kwtop] = 0.f;
*ns = 1;
*nd = 0;
/* Computing MAX */
r__2 = smlnum;
r__3 = ulp * (r__1 = h__[kwtop + kwtop * h_dim1], abs( r__1)); // , expr subst
if (abs(s) <= max(r__2,r__3))
{
*ns = 0;
*nd = 1;
if (kwtop > *ktop)
{
h__[kwtop + (kwtop - 1) * h_dim1] = 0.f;
}
}
work[1] = 1.f;
return 0;
}
/* ==== Convert to spike-triangular form. (In case of a */
/* . rare QR failure, this routine continues to do */
/* . aggressive early deflation using that part of */
/* . the deflation window that converged using INFQR */
/* . here and there to keep track.) ==== */
slacpy_("U", &jw, &jw, &h__[kwtop + kwtop * h_dim1], ldh, &t[t_offset], ldt);
i__1 = jw - 1;
i__2 = *ldh + 1;
i__3 = *ldt + 1;
scopy_(&i__1, &h__[kwtop + 1 + kwtop * h_dim1], &i__2, &t[t_dim1 + 2], & i__3);
slaset_("A", &jw, &jw, &c_b12, &c_b13, &v[v_offset], ldv);
slahqr_(&c_true, &c_true, &jw, &c__1, &jw, &t[t_offset], ldt, &sr[kwtop], &si[kwtop], &c__1, &jw, &v[v_offset], ldv, &infqr);
/* ==== STREXC needs a clean margin near the diagonal ==== */
i__1 = jw - 3;
for (j = 1;
j <= i__1;
++j)
{
t[j + 2 + j * t_dim1] = 0.f;
t[j + 3 + j * t_dim1] = 0.f;
/* L10: */
}
if (jw > 2)
{
t[jw + (jw - 2) * t_dim1] = 0.f;
}
/* ==== Deflation detection loop ==== */
*ns = jw;
ilst = infqr + 1;
L20:
if (ilst <= *ns)
{
if (*ns == 1)
{
bulge = FALSE_;
}
else
{
bulge = t[*ns + (*ns - 1) * t_dim1] != 0.f;
}
/* ==== Small spike tip test for deflation ==== */
if (! bulge)
{
/* ==== Real eigenvalue ==== */
foo = (r__1 = t[*ns + *ns * t_dim1], abs(r__1));
if (foo == 0.f)
{
foo = abs(s);
}
/* Computing MAX */
r__2 = smlnum;
r__3 = ulp * foo; // , expr subst
if ((r__1 = s * v[*ns * v_dim1 + 1], abs(r__1)) <= max(r__2,r__3))
{
/* ==== Deflatable ==== */
--(*ns);
}
else
{
/* ==== Undeflatable. Move it up out of the way. */
/* . (STREXC can not fail in this case.) ==== */
ifst = *ns;
strexc_("V", &jw, &t[t_offset], ldt, &v[v_offset], ldv, &ifst, &ilst, &work[1], &info);
++ilst;
}
}
else
{
/* ==== Complex conjugate pair ==== */
foo = (r__3 = t[*ns + *ns * t_dim1], abs(r__3)) + sqrt((r__1 = t[* ns + (*ns - 1) * t_dim1], abs(r__1))) * sqrt((r__2 = t[* ns - 1 + *ns * t_dim1], abs(r__2)));
if (foo == 0.f)
{
foo = abs(s);
}
/* Computing MAX */
r__3 = (r__1 = s * v[*ns * v_dim1 + 1], abs(r__1));
r__4 = (r__2 = s * v[(*ns - 1) * v_dim1 + 1], abs(r__2)); // , expr subst
/* Computing MAX */
r__5 = smlnum;
r__6 = ulp * foo; // , expr subst
if (max(r__3,r__4) <= max(r__5,r__6))
{
/* ==== Deflatable ==== */
*ns += -2;
}
else
{
/* ==== Undeflatable. Move them up out of the way. */
/* . Fortunately, STREXC does the right thing with */
/* . ILST in case of a rare exchange failure. ==== */
ifst = *ns;
strexc_("V", &jw, &t[t_offset], ldt, &v[v_offset], ldv, &ifst, &ilst, &work[1], &info);
ilst += 2;
}
}
/* ==== End deflation detection loop ==== */
goto L20;
}
/* ==== Return to Hessenberg form ==== */
if (*ns == 0)
{
s = 0.f;
}
if (*ns < jw)
{
/* ==== sorting diagonal blocks of T improves accuracy for */
/* . graded matrices. Bubble sort deals well with */
/* . exchange failures. ==== */
sorted = FALSE_;
i__ = *ns + 1;
L30:
if (sorted)
{
goto L50;
}
sorted = TRUE_;
kend = i__ - 1;
i__ = infqr + 1;
if (i__ == *ns)
{
k = i__ + 1;
}
else if (t[i__ + 1 + i__ * t_dim1] == 0.f)
{
k = i__ + 1;
}
else
{
k = i__ + 2;
}
L40:
if (k <= kend)
{
if (k == i__ + 1)
{
evi = (r__1 = t[i__ + i__ * t_dim1], abs(r__1));
}
else
{
evi = (r__3 = t[i__ + i__ * t_dim1], abs(r__3)) + sqrt((r__1 = t[i__ + 1 + i__ * t_dim1], abs(r__1))) * sqrt((r__2 = t[i__ + (i__ + 1) * t_dim1], abs(r__2)));
}
if (k == kend)
{
evk = (r__1 = t[k + k * t_dim1], abs(r__1));
}
else if (t[k + 1 + k * t_dim1] == 0.f)
{
evk = (r__1 = t[k + k * t_dim1], abs(r__1));
}
else
{
evk = (r__3 = t[k + k * t_dim1], abs(r__3)) + sqrt((r__1 = t[ k + 1 + k * t_dim1], abs(r__1))) * sqrt((r__2 = t[k + (k + 1) * t_dim1], abs(r__2)));
}
if (evi >= evk)
{
i__ = k;
}
else
{
sorted = FALSE_;
ifst = i__;
ilst = k;
strexc_("V", &jw, &t[t_offset], ldt, &v[v_offset], ldv, &ifst, &ilst, &work[1], &info);
if (info == 0)
{
i__ = ilst;
}
else
{
i__ = k;
}
}
if (i__ == kend)
{
k = i__ + 1;
}
else if (t[i__ + 1 + i__ * t_dim1] == 0.f)
{
k = i__ + 1;
}
else
{
k = i__ + 2;
}
goto L40;
}
goto L30;
L50:
;
}
/* ==== Restore shift/eigenvalue array from T ==== */
i__ = jw;
L60:
if (i__ >= infqr + 1)
{
if (i__ == infqr + 1)
{
sr[kwtop + i__ - 1] = t[i__ + i__ * t_dim1];
si[kwtop + i__ - 1] = 0.f;
--i__;
}
else if (t[i__ + (i__ - 1) * t_dim1] == 0.f)
{
sr[kwtop + i__ - 1] = t[i__ + i__ * t_dim1];
si[kwtop + i__ - 1] = 0.f;
--i__;
}
else
{
aa = t[i__ - 1 + (i__ - 1) * t_dim1];
cc = t[i__ + (i__ - 1) * t_dim1];
bb = t[i__ - 1 + i__ * t_dim1];
dd = t[i__ + i__ * t_dim1];
slanv2_(&aa, &bb, &cc, &dd, &sr[kwtop + i__ - 2], &si[kwtop + i__ - 2], &sr[kwtop + i__ - 1], &si[kwtop + i__ - 1], &cs, & sn);
i__ += -2;
}
goto L60;
}
if (*ns < jw || s == 0.f)
{
if (*ns > 1 && s != 0.f)
{
/* ==== Reflect spike back into lower triangle ==== */
scopy_(ns, &v[v_offset], ldv, &work[1], &c__1);
beta = work[1];
slarfg_(ns, &beta, &work[2], &c__1, &tau);
work[1] = 1.f;
i__1 = jw - 2;
i__2 = jw - 2;
slaset_("L", &i__1, &i__2, &c_b12, &c_b12, &t[t_dim1 + 3], ldt);
slarf_("L", ns, &jw, &work[1], &c__1, &tau, &t[t_offset], ldt, & work[jw + 1]);
slarf_("R", ns, ns, &work[1], &c__1, &tau, &t[t_offset], ldt, & work[jw + 1]);
slarf_("R", &jw, ns, &work[1], &c__1, &tau, &v[v_offset], ldv, & work[jw + 1]);
i__1 = *lwork - jw;
sgehrd_(&jw, &c__1, ns, &t[t_offset], ldt, &work[1], &work[jw + 1] , &i__1, &info);
}
/* ==== Copy updated reduced window into place ==== */
if (kwtop > 1)
{
h__[kwtop + (kwtop - 1) * h_dim1] = s * v[v_dim1 + 1];
}
slacpy_("U", &jw, &jw, &t[t_offset], ldt, &h__[kwtop + kwtop * h_dim1] , ldh);
i__1 = jw - 1;
i__2 = *ldt + 1;
i__3 = *ldh + 1;
scopy_(&i__1, &t[t_dim1 + 2], &i__2, &h__[kwtop + 1 + kwtop * h_dim1], &i__3);
/* ==== Accumulate orthogonal matrix in order update */
/* . H and Z, if requested. ==== */
if (*ns > 1 && s != 0.f)
{
i__1 = *lwork - jw;
sormhr_("R", "N", &jw, ns, &c__1, ns, &t[t_offset], ldt, &work[1], &v[v_offset], ldv, &work[jw + 1], &i__1, &info);
}
/* ==== Update vertical slab in H ==== */
if (*wantt)
{
ltop = 1;
}
else
{
ltop = *ktop;
}
i__1 = kwtop - 1;
i__2 = *nv;
for (krow = ltop;
i__2 < 0 ? krow >= i__1 : krow <= i__1;
krow += i__2)
{
/* Computing MIN */
i__3 = *nv;
i__4 = kwtop - krow; // , expr subst
kln = min(i__3,i__4);
sgemm_("N", "N", &kln, &jw, &jw, &c_b13, &h__[krow + kwtop * h_dim1], ldh, &v[v_offset], ldv, &c_b12, &wv[wv_offset], ldwv);
slacpy_("A", &kln, &jw, &wv[wv_offset], ldwv, &h__[krow + kwtop * h_dim1], ldh);
/* L70: */
}
/* ==== Update horizontal slab in H ==== */
if (*wantt)
{
i__2 = *n;
i__1 = *nh;
for (kcol = *kbot + 1;
i__1 < 0 ? kcol >= i__2 : kcol <= i__2;
kcol += i__1)
{
/* Computing MIN */
i__3 = *nh;
i__4 = *n - kcol + 1; // , expr subst
kln = min(i__3,i__4);
sgemm_("C", "N", &jw, &kln, &jw, &c_b13, &v[v_offset], ldv, & h__[kwtop + kcol * h_dim1], ldh, &c_b12, &t[t_offset], ldt);
slacpy_("A", &jw, &kln, &t[t_offset], ldt, &h__[kwtop + kcol * h_dim1], ldh);
/* L80: */
}
}
/* ==== Update vertical slab in Z ==== */
if (*wantz)
{
i__1 = *ihiz;
i__2 = *nv;
for (krow = *iloz;
i__2 < 0 ? krow >= i__1 : krow <= i__1;
krow += i__2)
{
/* Computing MIN */
i__3 = *nv;
i__4 = *ihiz - krow + 1; // , expr subst
kln = min(i__3,i__4);
sgemm_("N", "N", &kln, &jw, &jw, &c_b13, &z__[krow + kwtop * z_dim1], ldz, &v[v_offset], ldv, &c_b12, &wv[ wv_offset], ldwv);
slacpy_("A", &kln, &jw, &wv[wv_offset], ldwv, &z__[krow + kwtop * z_dim1], ldz);
/* L90: */
}
}
}
/* ==== Return the number of deflations ... ==== */
*nd = jw - *ns;
/* ==== ... and the number of shifts. (Subtracting */
/* . INFQR from the spike length takes care */
/* . of the case of a rare QR failure while */
/* . calculating eigenvalues of the deflation */
/* . window.) ==== */
*ns -= infqr;
/* ==== Return optimal workspace. ==== */
work[1] = (real) lwkopt;
/* ==== End of SLAQR2 ==== */
return 0;
}
/* ----------------------------------------------------------------------- */
/* Subroutine */ int sneupd_(logical *rvec, char *howmny, logical *select,
real *dr, real *di, real *z__, integer *ldz, real *sigmar, real *
sigmai, real *workev, char *bmat, integer *n, char *which, integer *
nev, real *tol, real *resid, integer *ncv, real *v, integer *ldv,
integer *iparam, integer *ipntr, real *workd, real *workl, integer *
lworkl, integer *info, ftnlen howmny_len, ftnlen bmat_len, ftnlen
which_len)
{
/* System generated locals */
integer v_dim1, v_offset, z_dim1, z_offset, i__1;
real r__1, r__2;
doublereal d__1;
/* Local variables */
static integer j, k, ih, jj, np;
static real vl[1] /* was [1][1] */;
static integer ibd, ldh, ldq, iri;
static real sep;
static integer irr, wri, wrr, mode;
static real eps23;
extern /* Subroutine */ int sger_(integer *, integer *, real *, real *,
integer *, real *, integer *, real *, integer *);
static integer ierr;
static real temp;
static integer iwev;
static char type__[6];
static real temp1;
extern doublereal snrm2_(integer *, real *, integer *);
static integer ihbds, iconj;
extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *);
static real conds;
static logical reord;
extern /* Subroutine */ int sgemv_(char *, integer *, integer *, real *,
real *, integer *, real *, integer *, real *, real *, integer *,
ftnlen);
static integer nconv, iwork[1];
static real rnorm;
extern /* Subroutine */ int scopy_(integer *, real *, integer *, real *,
integer *);
static integer ritzi;
extern /* Subroutine */ int strmm_(char *, char *, char *, char *,
integer *, integer *, real *, real *, integer *, real *, integer *
, ftnlen, ftnlen, ftnlen, ftnlen), ivout_(integer *, integer *,
integer *, integer *, char *, ftnlen), smout_(integer *, integer *
, integer *, real *, integer *, integer *, char *, ftnlen);
static integer ritzr;
extern /* Subroutine */ int svout_(integer *, integer *, real *, integer *
, char *, ftnlen), sgeqr2_(integer *, integer *, real *, integer *
, real *, real *, integer *);
static integer nconv2;
extern doublereal slapy2_(real *, real *);
extern /* Subroutine */ int sorm2r_(char *, char *, integer *, integer *,
integer *, real *, integer *, real *, real *, integer *, real *,
integer *, ftnlen, ftnlen);
static integer iheigi, iheigr, bounds, invsub, iuptri, msglvl, outncv,
ishift, numcnv;
extern /* Subroutine */ int slacpy_(char *, integer *, integer *, real *,
integer *, real *, integer *, ftnlen), slahqr_(logical *, logical
*, integer *, integer *, integer *, real *, integer *, real *,
real *, integer *, integer *, real *, integer *, integer *),
slaset_(char *, integer *, integer *, real *, real *, real *,
integer *, ftnlen), strevc_(char *, char *, logical *, integer *,
real *, integer *, real *, integer *, real *, integer *, integer *
, integer *, real *, integer *, ftnlen, ftnlen), strsen_(char *,
char *, logical *, integer *, real *, integer *, real *, integer *
, real *, real *, integer *, real *, real *, real *, integer *,
integer *, integer *, integer *, ftnlen, ftnlen);
extern doublereal slamch_(char *, ftnlen);
extern /* Subroutine */ int sngets_(integer *, char *, integer *, integer
*, real *, real *, real *, real *, real *, ftnlen);
/* %----------------------------------------------------% */
/* | Include files for debugging and timing information | */
/* %----------------------------------------------------% */
/* \SCCS Information: @(#) */
/* FILE: debug.h SID: 2.3 DATE OF SID: 11/16/95 RELEASE: 2 */
/* %---------------------------------% */
/* | See debug.doc for documentation | */
/* %---------------------------------% */
/* %------------------% */
/* | Scalar Arguments | */
/* %------------------% */
/* %--------------------------------% */
/* | See stat.doc for documentation | */
/* %--------------------------------% */
/* \SCCS Information: @(#) */
/* FILE: stat.h SID: 2.2 DATE OF SID: 11/16/95 RELEASE: 2 */
/* %-----------------% */
/* | Array Arguments | */
/* %-----------------% */
/* %------------% */
/* | Parameters | */
/* %------------% */
/* %---------------% */
/* | Local Scalars | */
/* %---------------% */
/* %----------------------% */
/* | External Subroutines | */
/* %----------------------% */
/* %--------------------% */
/* | External Functions | */
/* %--------------------% */
/* %---------------------% */
/* | Intrinsic Functions | */
/* %---------------------% */
/* %-----------------------% */
/* | Executable Statements | */
/* %-----------------------% */
/* %------------------------% */
/* | Set default parameters | */
/* %------------------------% */
/* Parameter adjustments */
z_dim1 = *ldz;
z_offset = 1 + z_dim1;
z__ -= z_offset;
--workd;
--resid;
--di;
--dr;
--workev;
--select;
v_dim1 = *ldv;
v_offset = 1 + v_dim1;
v -= v_offset;
--iparam;
--ipntr;
--workl;
/* Function Body */
msglvl = debug_1.mneupd;
mode = iparam[7];
nconv = iparam[5];
*info = 0;
/* %---------------------------------% */
/* | Get machine dependent constant. | */
/* %---------------------------------% */
eps23 = slamch_("Epsilon-Machine", (ftnlen)15);
d__1 = (doublereal) eps23;
eps23 = pow_dd(&d__1, &c_b3);
/* %--------------% */
/* | Quick return | */
/* %--------------% */
ierr = 0;
if (nconv <= 0) {
ierr = -14;
} else if (*n <= 0) {
ierr = -1;
} else if (*nev <= 0) {
ierr = -2;
} else if (*ncv <= *nev + 1 || *ncv > *n) {
ierr = -3;
} else if (s_cmp(which, "LM", (ftnlen)2, (ftnlen)2) != 0 && s_cmp(which,
"SM", (ftnlen)2, (ftnlen)2) != 0 && s_cmp(which, "LR", (ftnlen)2,
(ftnlen)2) != 0 && s_cmp(which, "SR", (ftnlen)2, (ftnlen)2) != 0
&& s_cmp(which, "LI", (ftnlen)2, (ftnlen)2) != 0 && s_cmp(which,
"SI", (ftnlen)2, (ftnlen)2) != 0) {
ierr = -5;
} else if (*(unsigned char *)bmat != 'I' && *(unsigned char *)bmat != 'G')
{
ierr = -6;
} else /* if(complicated condition) */ {
/* Computing 2nd power */
i__1 = *ncv;
if (*lworkl < i__1 * i__1 * 3 + *ncv * 6) {
ierr = -7;
} else if (*(unsigned char *)howmny != 'A' && *(unsigned char *)
howmny != 'P' && *(unsigned char *)howmny != 'S' && *rvec) {
ierr = -13;
} else if (*(unsigned char *)howmny == 'S') {
ierr = -12;
}
}
if (mode == 1 || mode == 2) {
s_copy(type__, "REGULR", (ftnlen)6, (ftnlen)6);
} else if (mode == 3 && *sigmai == 0.f) {
s_copy(type__, "SHIFTI", (ftnlen)6, (ftnlen)6);
} else if (mode == 3) {
s_copy(type__, "REALPT", (ftnlen)6, (ftnlen)6);
} else if (mode == 4) {
s_copy(type__, "IMAGPT", (ftnlen)6, (ftnlen)6);
} else {
ierr = -10;
}
if (mode == 1 && *(unsigned char *)bmat == 'G') {
ierr = -11;
}
/* %------------% */
/* | Error Exit | */
/* %------------% */
if (ierr != 0) {
*info = ierr;
goto L9000;
}
/* %--------------------------------------------------------% */
/* | Pointer into WORKL for address of H, RITZ, BOUNDS, Q | */
/* | etc... and the remaining workspace. | */
/* | Also update pointer to be used on output. | */
/* | Memory is laid out as follows: | */
/* | workl(1:ncv*ncv) := generated Hessenberg matrix | */
/* | workl(ncv*ncv+1:ncv*ncv+2*ncv) := real and imaginary | */
/* | parts of ritz values | */
/* | workl(ncv*ncv+2*ncv+1:ncv*ncv+3*ncv) := error bounds | */
/* %--------------------------------------------------------% */
/* %-----------------------------------------------------------% */
/* | The following is used and set by SNEUPD. | */
/* | workl(ncv*ncv+3*ncv+1:ncv*ncv+4*ncv) := The untransformed | */
/* | real part of the Ritz values. | */
/* | workl(ncv*ncv+4*ncv+1:ncv*ncv+5*ncv) := The untransformed | */
/* | imaginary part of the Ritz values. | */
/* | workl(ncv*ncv+5*ncv+1:ncv*ncv+6*ncv) := The untransformed | */
/* | error bounds of the Ritz values | */
/* | workl(ncv*ncv+6*ncv+1:2*ncv*ncv+6*ncv) := Holds the upper | */
/* | quasi-triangular matrix for H | */
/* | workl(2*ncv*ncv+6*ncv+1: 3*ncv*ncv+6*ncv) := Holds the | */
/* | associated matrix representation of the invariant | */
/* | subspace for H. | */
/* | GRAND total of NCV * ( 3 * NCV + 6 ) locations. | */
/* %-----------------------------------------------------------% */
ih = ipntr[5];
ritzr = ipntr[6];
ritzi = ipntr[7];
bounds = ipntr[8];
ldh = *ncv;
ldq = *ncv;
iheigr = bounds + ldh;
iheigi = iheigr + ldh;
ihbds = iheigi + ldh;
iuptri = ihbds + ldh;
invsub = iuptri + ldh * *ncv;
ipntr[9] = iheigr;
ipntr[10] = iheigi;
ipntr[11] = ihbds;
ipntr[12] = iuptri;
ipntr[13] = invsub;
wrr = 1;
wri = *ncv + 1;
iwev = wri + *ncv;
/* %-----------------------------------------% */
/* | irr points to the REAL part of the Ritz | */
/* | values computed by _neigh before | */
/* | exiting _naup2. | */
/* | iri points to the IMAGINARY part of the | */
/* | Ritz values computed by _neigh | */
/* | before exiting _naup2. | */
/* | ibd points to the Ritz estimates | */
/* | computed by _neigh before exiting | */
/* | _naup2. | */
/* %-----------------------------------------% */
irr = ipntr[14] + *ncv * *ncv;
iri = irr + *ncv;
ibd = iri + *ncv;
/* %------------------------------------% */
/* | RNORM is B-norm of the RESID(1:N). | */
/* %------------------------------------% */
rnorm = workl[ih + 2];
workl[ih + 2] = 0.f;
if (msglvl > 2) {
svout_(&debug_1.logfil, ncv, &workl[irr], &debug_1.ndigit, "_neupd: "
"Real part of Ritz values passed in from _NAUPD.", (ftnlen)55);
svout_(&debug_1.logfil, ncv, &workl[iri], &debug_1.ndigit, "_neupd: "
"Imag part of Ritz values passed in from _NAUPD.", (ftnlen)55);
svout_(&debug_1.logfil, ncv, &workl[ibd], &debug_1.ndigit, "_neupd: "
"Ritz estimates passed in from _NAUPD.", (ftnlen)45);
}
if (*rvec) {
reord = FALSE_;
/* %---------------------------------------------------% */
/* | Use the temporary bounds array to store indices | */
/* | These will be used to mark the select array later | */
/* %---------------------------------------------------% */
i__1 = *ncv;
for (j = 1; j <= i__1; ++j) {
workl[bounds + j - 1] = (real) j;
select[j] = FALSE_;
/* L10: */
}
/* %-------------------------------------% */
/* | Select the wanted Ritz values. | */
/* | Sort the Ritz values so that the | */
/* | wanted ones appear at the tailing | */
/* | NEV positions of workl(irr) and | */
/* | workl(iri). Move the corresponding | */
/* | error estimates in workl(bound) | */
/* | accordingly. | */
/* %-------------------------------------% */
np = *ncv - *nev;
ishift = 0;
sngets_(&ishift, which, nev, &np, &workl[irr], &workl[iri], &workl[
bounds], &workl[1], &workl[np + 1], (ftnlen)2);
if (msglvl > 2) {
svout_(&debug_1.logfil, ncv, &workl[irr], &debug_1.ndigit, "_neu"
"pd: Real part of Ritz values after calling _NGETS.", (
ftnlen)54);
svout_(&debug_1.logfil, ncv, &workl[iri], &debug_1.ndigit, "_neu"
"pd: Imag part of Ritz values after calling _NGETS.", (
ftnlen)54);
svout_(&debug_1.logfil, ncv, &workl[bounds], &debug_1.ndigit,
"_neupd: Ritz value indices after calling _NGETS.", (
ftnlen)48);
}
/* %-----------------------------------------------------% */
/* | Record indices of the converged wanted Ritz values | */
/* | Mark the select array for possible reordering | */
/* %-----------------------------------------------------% */
numcnv = 0;
i__1 = *ncv;
for (j = 1; j <= i__1; ++j) {
/* Computing MAX */
r__1 = eps23, r__2 = slapy2_(&workl[irr + *ncv - j], &workl[iri +
*ncv - j]);
temp1 = dmax(r__1,r__2);
jj = workl[bounds + *ncv - j];
if (numcnv < nconv && workl[ibd + jj - 1] <= *tol * temp1) {
select[jj] = TRUE_;
++numcnv;
if (jj > nconv) {
reord = TRUE_;
}
}
/* L11: */
}
/* %-----------------------------------------------------------% */
/* | Check the count (numcnv) of converged Ritz values with | */
/* | the number (nconv) reported by dnaupd. If these two | */
/* | are different then there has probably been an error | */
/* | caused by incorrect passing of the dnaupd data. | */
/* %-----------------------------------------------------------% */
if (msglvl > 2) {
ivout_(&debug_1.logfil, &c__1, &numcnv, &debug_1.ndigit, "_neupd"
": Number of specified eigenvalues", (ftnlen)39);
ivout_(&debug_1.logfil, &c__1, &nconv, &debug_1.ndigit, "_neupd:"
" Number of \"converged\" eigenvalues", (ftnlen)41);
}
if (numcnv != nconv) {
*info = -15;
goto L9000;
}
/* %-----------------------------------------------------------% */
/* | Call LAPACK routine slahqr to compute the real Schur form | */
/* | of the upper Hessenberg matrix returned by SNAUPD. | */
/* | Make a copy of the upper Hessenberg matrix. | */
/* | Initialize the Schur vector matrix Q to the identity. | */
/* %-----------------------------------------------------------% */
i__1 = ldh * *ncv;
scopy_(&i__1, &workl[ih], &c__1, &workl[iuptri], &c__1);
slaset_("All", ncv, ncv, &c_b37, &c_b38, &workl[invsub], &ldq, (
ftnlen)3);
slahqr_(&c_true, &c_true, ncv, &c__1, ncv, &workl[iuptri], &ldh, &
workl[iheigr], &workl[iheigi], &c__1, ncv, &workl[invsub], &
ldq, &ierr);
scopy_(ncv, &workl[invsub + *ncv - 1], &ldq, &workl[ihbds], &c__1);
if (ierr != 0) {
*info = -8;
goto L9000;
}
if (msglvl > 1) {
svout_(&debug_1.logfil, ncv, &workl[iheigr], &debug_1.ndigit,
"_neupd: Real part of the eigenvalues of H", (ftnlen)41);
svout_(&debug_1.logfil, ncv, &workl[iheigi], &debug_1.ndigit,
"_neupd: Imaginary part of the Eigenvalues of H", (ftnlen)
46);
svout_(&debug_1.logfil, ncv, &workl[ihbds], &debug_1.ndigit,
"_neupd: Last row of the Schur vector matrix", (ftnlen)43)
;
if (msglvl > 3) {
smout_(&debug_1.logfil, ncv, ncv, &workl[iuptri], &ldh, &
debug_1.ndigit, "_neupd: The upper quasi-triangular "
"matrix ", (ftnlen)42);
}
}
if (reord) {
/* %-----------------------------------------------------% */
/* | Reorder the computed upper quasi-triangular matrix. | */
/* %-----------------------------------------------------% */
strsen_("None", "V", &select[1], ncv, &workl[iuptri], &ldh, &
workl[invsub], &ldq, &workl[iheigr], &workl[iheigi], &
nconv2, &conds, &sep, &workl[ihbds], ncv, iwork, &c__1, &
ierr, (ftnlen)4, (ftnlen)1);
if (nconv2 < nconv) {
nconv = nconv2;
}
if (ierr == 1) {
*info = 1;
goto L9000;
}
if (msglvl > 2) {
svout_(&debug_1.logfil, ncv, &workl[iheigr], &debug_1.ndigit,
"_neupd: Real part of the eigenvalues of H--reordered"
, (ftnlen)52);
svout_(&debug_1.logfil, ncv, &workl[iheigi], &debug_1.ndigit,
"_neupd: Imag part of the eigenvalues of H--reordered"
, (ftnlen)52);
if (msglvl > 3) {
smout_(&debug_1.logfil, ncv, ncv, &workl[iuptri], &ldq, &
debug_1.ndigit, "_neupd: Quasi-triangular matrix"
" after re-ordering", (ftnlen)49);
}
}
}
/* %---------------------------------------% */
/* | Copy the last row of the Schur vector | */
/* | into workl(ihbds). This will be used | */
/* | to compute the Ritz estimates of | */
/* | converged Ritz values. | */
/* %---------------------------------------% */
scopy_(ncv, &workl[invsub + *ncv - 1], &ldq, &workl[ihbds], &c__1);
/* %----------------------------------------------------% */
/* | Place the computed eigenvalues of H into DR and DI | */
/* | if a spectral transformation was not used. | */
/* %----------------------------------------------------% */
if (s_cmp(type__, "REGULR", (ftnlen)6, (ftnlen)6) == 0) {
scopy_(&nconv, &workl[iheigr], &c__1, &dr[1], &c__1);
scopy_(&nconv, &workl[iheigi], &c__1, &di[1], &c__1);
}
/* %----------------------------------------------------------% */
/* | Compute the QR factorization of the matrix representing | */
/* | the wanted invariant subspace located in the first NCONV | */
/* | columns of workl(invsub,ldq). | */
/* %----------------------------------------------------------% */
sgeqr2_(ncv, &nconv, &workl[invsub], &ldq, &workev[1], &workev[*ncv +
1], &ierr);
/* %---------------------------------------------------------% */
/* | * Postmultiply V by Q using sorm2r. | */
/* | * Copy the first NCONV columns of VQ into Z. | */
/* | * Postmultiply Z by R. | */
/* | The N by NCONV matrix Z is now a matrix representation | */
/* | of the approximate invariant subspace associated with | */
/* | the Ritz values in workl(iheigr) and workl(iheigi) | */
/* | The first NCONV columns of V are now approximate Schur | */
/* | vectors associated with the real upper quasi-triangular | */
/* | matrix of order NCONV in workl(iuptri) | */
/* %---------------------------------------------------------% */
sorm2r_("Right", "Notranspose", n, ncv, &nconv, &workl[invsub], &ldq,
&workev[1], &v[v_offset], ldv, &workd[*n + 1], &ierr, (ftnlen)
5, (ftnlen)11);
slacpy_("All", n, &nconv, &v[v_offset], ldv, &z__[z_offset], ldz, (
ftnlen)3);
i__1 = nconv;
for (j = 1; j <= i__1; ++j) {
/* %---------------------------------------------------% */
/* | Perform both a column and row scaling if the | */
/* | diagonal element of workl(invsub,ldq) is negative | */
/* | I'm lazy and don't take advantage of the upper | */
/* | quasi-triangular form of workl(iuptri,ldq) | */
/* | Note that since Q is orthogonal, R is a diagonal | */
/* | matrix consisting of plus or minus ones | */
/* %---------------------------------------------------% */
if (workl[invsub + (j - 1) * ldq + j - 1] < 0.f) {
sscal_(&nconv, &c_b64, &workl[iuptri + j - 1], &ldq);
sscal_(&nconv, &c_b64, &workl[iuptri + (j - 1) * ldq], &c__1);
}
/* L20: */
}
if (*(unsigned char *)howmny == 'A') {
/* %--------------------------------------------% */
/* | Compute the NCONV wanted eigenvectors of T | */
/* | located in workl(iuptri,ldq). | */
/* %--------------------------------------------% */
i__1 = *ncv;
for (j = 1; j <= i__1; ++j) {
if (j <= nconv) {
select[j] = TRUE_;
} else {
select[j] = FALSE_;
}
/* L30: */
}
strevc_("Right", "Select", &select[1], ncv, &workl[iuptri], &ldq,
vl, &c__1, &workl[invsub], &ldq, ncv, &outncv, &workev[1],
&ierr, (ftnlen)5, (ftnlen)6);
if (ierr != 0) {
*info = -9;
goto L9000;
}
/* %------------------------------------------------% */
/* | Scale the returning eigenvectors so that their | */
/* | Euclidean norms are all one. LAPACK subroutine | */
/* | strevc returns each eigenvector normalized so | */
/* | that the element of largest magnitude has | */
/* | magnitude 1; | */
/* %------------------------------------------------% */
iconj = 0;
i__1 = nconv;
for (j = 1; j <= i__1; ++j) {
if (workl[iheigi + j - 1] == 0.f) {
/* %----------------------% */
/* | real eigenvalue case | */
/* %----------------------% */
temp = snrm2_(ncv, &workl[invsub + (j - 1) * ldq], &c__1);
r__1 = 1.f / temp;
sscal_(ncv, &r__1, &workl[invsub + (j - 1) * ldq], &c__1);
} else {
/* %-------------------------------------------% */
/* | Complex conjugate pair case. Note that | */
/* | since the real and imaginary part of | */
/* | the eigenvector are stored in consecutive | */
/* | columns, we further normalize by the | */
/* | square root of two. | */
/* %-------------------------------------------% */
if (iconj == 0) {
r__1 = snrm2_(ncv, &workl[invsub + (j - 1) * ldq], &
c__1);
r__2 = snrm2_(ncv, &workl[invsub + j * ldq], &c__1);
temp = slapy2_(&r__1, &r__2);
r__1 = 1.f / temp;
sscal_(ncv, &r__1, &workl[invsub + (j - 1) * ldq], &
c__1);
r__1 = 1.f / temp;
sscal_(ncv, &r__1, &workl[invsub + j * ldq], &c__1);
iconj = 1;
} else {
iconj = 0;
}
}
/* L40: */
}
sgemv_("T", ncv, &nconv, &c_b38, &workl[invsub], &ldq, &workl[
ihbds], &c__1, &c_b37, &workev[1], &c__1, (ftnlen)1);
iconj = 0;
i__1 = nconv;
for (j = 1; j <= i__1; ++j) {
if (workl[iheigi + j - 1] != 0.f) {
/* %-------------------------------------------% */
/* | Complex conjugate pair case. Note that | */
/* | since the real and imaginary part of | */
/* | the eigenvector are stored in consecutive | */
/* %-------------------------------------------% */
if (iconj == 0) {
workev[j] = slapy2_(&workev[j], &workev[j + 1]);
workev[j + 1] = workev[j];
iconj = 1;
} else {
iconj = 0;
}
}
/* L45: */
}
if (msglvl > 2) {
scopy_(ncv, &workl[invsub + *ncv - 1], &ldq, &workl[ihbds], &
c__1);
svout_(&debug_1.logfil, ncv, &workl[ihbds], &debug_1.ndigit,
"_neupd: Last row of the eigenvector matrix for T", (
ftnlen)48);
if (msglvl > 3) {
smout_(&debug_1.logfil, ncv, ncv, &workl[invsub], &ldq, &
debug_1.ndigit, "_neupd: The eigenvector matrix "
"for T", (ftnlen)36);
}
}
/* %---------------------------------------% */
/* | Copy Ritz estimates into workl(ihbds) | */
/* %---------------------------------------% */
scopy_(&nconv, &workev[1], &c__1, &workl[ihbds], &c__1);
/* %---------------------------------------------------------% */
/* | Compute the QR factorization of the eigenvector matrix | */
/* | associated with leading portion of T in the first NCONV | */
/* | columns of workl(invsub,ldq). | */
/* %---------------------------------------------------------% */
sgeqr2_(ncv, &nconv, &workl[invsub], &ldq, &workev[1], &workev[*
ncv + 1], &ierr);
/* %----------------------------------------------% */
/* | * Postmultiply Z by Q. | */
/* | * Postmultiply Z by R. | */
/* | The N by NCONV matrix Z is now contains the | */
/* | Ritz vectors associated with the Ritz values | */
/* | in workl(iheigr) and workl(iheigi). | */
/* %----------------------------------------------% */
sorm2r_("Right", "Notranspose", n, ncv, &nconv, &workl[invsub], &
ldq, &workev[1], &z__[z_offset], ldz, &workd[*n + 1], &
ierr, (ftnlen)5, (ftnlen)11);
strmm_("Right", "Upper", "No transpose", "Non-unit", n, &nconv, &
c_b38, &workl[invsub], &ldq, &z__[z_offset], ldz, (ftnlen)
5, (ftnlen)5, (ftnlen)12, (ftnlen)8);
}
} else {
/* %------------------------------------------------------% */
/* | An approximate invariant subspace is not needed. | */
/* | Place the Ritz values computed SNAUPD into DR and DI | */
/* %------------------------------------------------------% */
scopy_(&nconv, &workl[ritzr], &c__1, &dr[1], &c__1);
scopy_(&nconv, &workl[ritzi], &c__1, &di[1], &c__1);
scopy_(&nconv, &workl[ritzr], &c__1, &workl[iheigr], &c__1);
scopy_(&nconv, &workl[ritzi], &c__1, &workl[iheigi], &c__1);
scopy_(&nconv, &workl[bounds], &c__1, &workl[ihbds], &c__1);
}
/* %------------------------------------------------% */
/* | Transform the Ritz values and possibly vectors | */
/* | and corresponding error bounds of OP to those | */
/* | of A*x = lambda*B*x. | */
/* %------------------------------------------------% */
if (s_cmp(type__, "REGULR", (ftnlen)6, (ftnlen)6) == 0) {
if (*rvec) {
sscal_(ncv, &rnorm, &workl[ihbds], &c__1);
}
} else {
/* %---------------------------------------% */
/* | A spectral transformation was used. | */
/* | * Determine the Ritz estimates of the | */
/* | Ritz values in the original system. | */
/* %---------------------------------------% */
if (s_cmp(type__, "SHIFTI", (ftnlen)6, (ftnlen)6) == 0) {
if (*rvec) {
sscal_(ncv, &rnorm, &workl[ihbds], &c__1);
}
i__1 = *ncv;
for (k = 1; k <= i__1; ++k) {
temp = slapy2_(&workl[iheigr + k - 1], &workl[iheigi + k - 1])
;
workl[ihbds + k - 1] = (r__1 = workl[ihbds + k - 1], dabs(
r__1)) / temp / temp;
/* L50: */
}
} else if (s_cmp(type__, "REALPT", (ftnlen)6, (ftnlen)6) == 0) {
i__1 = *ncv;
for (k = 1; k <= i__1; ++k) {
/* L60: */
}
} else if (s_cmp(type__, "IMAGPT", (ftnlen)6, (ftnlen)6) == 0) {
i__1 = *ncv;
for (k = 1; k <= i__1; ++k) {
/* L70: */
}
}
/* %-----------------------------------------------------------% */
/* | * Transform the Ritz values back to the original system. | */
/* | For TYPE = 'SHIFTI' the transformation is | */
/* | lambda = 1/theta + sigma | */
/* | For TYPE = 'REALPT' or 'IMAGPT' the user must from | */
/* | Rayleigh quotients or a projection. See remark 3 above.| */
/* | NOTES: | */
/* | *The Ritz vectors are not affected by the transformation. | */
/* %-----------------------------------------------------------% */
if (s_cmp(type__, "SHIFTI", (ftnlen)6, (ftnlen)6) == 0) {
i__1 = *ncv;
for (k = 1; k <= i__1; ++k) {
temp = slapy2_(&workl[iheigr + k - 1], &workl[iheigi + k - 1])
;
workl[iheigr + k - 1] = workl[iheigr + k - 1] / temp / temp +
*sigmar;
workl[iheigi + k - 1] = -workl[iheigi + k - 1] / temp / temp
+ *sigmai;
/* L80: */
}
scopy_(&nconv, &workl[iheigr], &c__1, &dr[1], &c__1);
scopy_(&nconv, &workl[iheigi], &c__1, &di[1], &c__1);
} else if (s_cmp(type__, "REALPT", (ftnlen)6, (ftnlen)6) == 0 ||
s_cmp(type__, "IMAGPT", (ftnlen)6, (ftnlen)6) == 0) {
scopy_(&nconv, &workl[iheigr], &c__1, &dr[1], &c__1);
scopy_(&nconv, &workl[iheigi], &c__1, &di[1], &c__1);
}
}
if (s_cmp(type__, "SHIFTI", (ftnlen)6, (ftnlen)6) == 0 && msglvl > 1) {
svout_(&debug_1.logfil, &nconv, &dr[1], &debug_1.ndigit, "_neupd: Un"
"transformed real part of the Ritz valuess.", (ftnlen)52);
svout_(&debug_1.logfil, &nconv, &di[1], &debug_1.ndigit, "_neupd: Un"
"transformed imag part of the Ritz valuess.", (ftnlen)52);
svout_(&debug_1.logfil, &nconv, &workl[ihbds], &debug_1.ndigit, "_ne"
"upd: Ritz estimates of untransformed Ritz values.", (ftnlen)
52);
} else if (s_cmp(type__, "REGULR", (ftnlen)6, (ftnlen)6) == 0 && msglvl >
1) {
svout_(&debug_1.logfil, &nconv, &dr[1], &debug_1.ndigit, "_neupd: Re"
"al parts of converged Ritz values.", (ftnlen)44);
svout_(&debug_1.logfil, &nconv, &di[1], &debug_1.ndigit, "_neupd: Im"
"ag parts of converged Ritz values.", (ftnlen)44);
svout_(&debug_1.logfil, &nconv, &workl[ihbds], &debug_1.ndigit, "_ne"
"upd: Associated Ritz estimates.", (ftnlen)34);
}
/* %-------------------------------------------------% */
/* | Eigenvector Purification step. Formally perform | */
/* | one of inverse subspace iteration. Only used | */
/* | for MODE = 2. | */
/* %-------------------------------------------------% */
if (*rvec && *(unsigned char *)howmny == 'A' && s_cmp(type__, "SHIFTI", (
ftnlen)6, (ftnlen)6) == 0) {
/* %------------------------------------------------% */
/* | Purify the computed Ritz vectors by adding a | */
/* | little bit of the residual vector: | */
/* | T | */
/* | resid(:)*( e s ) / theta | */
/* | NCV | */
/* | where H s = s theta. Remember that when theta | */
/* | has nonzero imaginary part, the corresponding | */
/* | Ritz vector is stored across two columns of Z. | */
/* %------------------------------------------------% */
iconj = 0;
i__1 = nconv;
for (j = 1; j <= i__1; ++j) {
if (workl[iheigi + j - 1] == 0.f) {
workev[j] = workl[invsub + (j - 1) * ldq + *ncv - 1] / workl[
iheigr + j - 1];
} else if (iconj == 0) {
temp = slapy2_(&workl[iheigr + j - 1], &workl[iheigi + j - 1])
;
workev[j] = (workl[invsub + (j - 1) * ldq + *ncv - 1] * workl[
iheigr + j - 1] + workl[invsub + j * ldq + *ncv - 1] *
workl[iheigi + j - 1]) / temp / temp;
workev[j + 1] = (workl[invsub + j * ldq + *ncv - 1] * workl[
iheigr + j - 1] - workl[invsub + (j - 1) * ldq + *ncv
- 1] * workl[iheigi + j - 1]) / temp / temp;
iconj = 1;
} else {
iconj = 0;
}
/* L110: */
}
/* %---------------------------------------% */
/* | Perform a rank one update to Z and | */
/* | purify all the Ritz vectors together. | */
/* %---------------------------------------% */
sger_(n, &nconv, &c_b38, &resid[1], &c__1, &workev[1], &c__1, &z__[
z_offset], ldz);
}
L9000:
return 0;
/* %---------------% */
/* | End of SNEUPD | */
/* %---------------% */
} /* sneupd_ */
/* Subroutine */ int slaqr2_(logical *wantt, logical *wantz, integer *n,
integer *ktop, integer *kbot, integer *nw, real *h__, integer *ldh,
integer *iloz, integer *ihiz, real *z__, integer *ldz, integer *ns,
integer *nd, real *sr, real *si, real *v, integer *ldv, integer *nh,
real *t, integer *ldt, integer *nv, real *wv, integer *ldwv, real *
work, integer *lwork)
{
/* System generated locals */
integer h_dim1, h_offset, t_dim1, t_offset, v_dim1, v_offset, wv_dim1,
wv_offset, z_dim1, z_offset, i__1, i__2, i__3, i__4;
real r__1, r__2, r__3, r__4, r__5, r__6;
/* Local variables */
integer i__, j, k;
real s, aa, bb, cc, dd, cs, sn;
integer jw;
real evi, evk, foo;
integer kln;
real tau, ulp;
integer lwk1, lwk2;
real beta;
integer kend, kcol, info, ifst, ilst, ltop, krow;
logical bulge;
integer infqr;
integer kwtop;
real safmin;
real safmax;
logical sorted;
real smlnum;
integer lwkopt;
/* -- LAPACK auxiliary routine (version 3.2.1) -- */
/* -- April 2009 -- */
/* This subroutine is identical to SLAQR3 except that it avoids */
/* recursion by calling SLAHQR instead of SLAQR4. */
/* ****************************************************************** */
/* Aggressive early deflation: */
/* This subroutine accepts as input an upper Hessenberg matrix */
/* H and performs an orthogonal similarity transformation */
/* designed to detect and deflate fully converged eigenvalues from */
/* a trailing principal submatrix. On output H has been over- */
/* written by a new Hessenberg matrix that is a perturbation of */
/* an orthogonal similarity transformation of H. It is to be */
/* hoped that the final version of H has many zero subdiagonal */
/* entries. */
/* ****************************************************************** */
/* WANTT (input) LOGICAL */
/* If .TRUE., then the Hessenberg matrix H is fully updated */
/* so that the quasi-triangular Schur factor may be */
/* computed (in cooperation with the calling subroutine). */
/* If .FALSE., then only enough of H is updated to preserve */
/* the eigenvalues. */
/* WANTZ (input) LOGICAL */
/* If .TRUE., then the orthogonal matrix Z is updated so */
/* so that the orthogonal Schur factor may be computed */
/* (in cooperation with the calling subroutine). */
/* If .FALSE., then Z is not referenced. */
/* N (input) INTEGER */
/* The order of the matrix H and (if WANTZ is .TRUE.) the */
/* order of the orthogonal matrix Z. */
/* KTOP (input) INTEGER */
/* It is assumed that either KTOP = 1 or H(KTOP,KTOP-1)=0. */
/* KBOT and KTOP together determine an isolated block */
/* along the diagonal of the Hessenberg matrix. */
/* KBOT (input) INTEGER */
/* It is assumed without a check that either */
/* KBOT = N or H(KBOT+1,KBOT)=0. KBOT and KTOP together */
/* determine an isolated block along the diagonal of the */
/* Hessenberg matrix. */
/* NW (input) INTEGER */
/* Deflation window size. 1 .LE. NW .LE. (KBOT-KTOP+1). */
/* H (input/output) REAL array, dimension (LDH,N) */
/* On input the initial N-by-N section of H stores the */
/* Hessenberg matrix undergoing aggressive early deflation. */
/* On output H has been transformed by an orthogonal */
/* similarity transformation, perturbed, and the returned */
/* to Hessenberg form that (it is to be hoped) has some */
/* zero subdiagonal entries. */
/* LDH (input) integer */
/* Leading dimension of H just as declared in the calling */
/* subroutine. N .LE. LDH */
/* ILOZ (input) INTEGER */
/* IHIZ (input) INTEGER */
/* Specify the rows of Z to which transformations must be */
/* Z (input/output) REAL array, dimension (LDZ,N) */
/* IF WANTZ is .TRUE., then on output, the orthogonal */
/* similarity transformation mentioned above has been */
/* accumulated into Z(ILOZ:IHIZ,ILO:IHI) from the right. */
/* If WANTZ is .FALSE., then Z is unreferenced. */
/* LDZ (input) integer */
/* The leading dimension of Z just as declared in the */
/* calling subroutine. 1 .LE. LDZ. */
/* NS (output) integer */
/* The number of unconverged (ie approximate) eigenvalues */
/* returned in SR and SI that may be used as shifts by the */
/* calling subroutine. */
/* ND (output) integer */
/* The number of converged eigenvalues uncovered by this */
/* subroutine. */
/* SR (output) REAL array, dimension KBOT */
/* SI (output) REAL array, dimension KBOT */
/* On output, the real and imaginary parts of approximate */
/* eigenvalues that may be used for shifts are stored in */
/* SR(KBOT-ND-NS+1) through SR(KBOT-ND) and */
/* SI(KBOT-ND-NS+1) through SI(KBOT-ND), respectively. */
/* The real and imaginary parts of converged eigenvalues */
/* are stored in SR(KBOT-ND+1) through SR(KBOT) and */
/* SI(KBOT-ND+1) through SI(KBOT), respectively. */
/* V (workspace) REAL array, dimension (LDV,NW) */
/* An NW-by-NW work array. */
/* LDV (input) integer scalar */
/* The leading dimension of V just as declared in the */
/* calling subroutine. NW .LE. LDV */
/* NH (input) integer scalar */
/* The number of columns of T. NH.GE.NW. */
/* T (workspace) REAL array, dimension (LDT,NW) */
/* LDT (input) integer */
/* The leading dimension of T just as declared in the */
/* calling subroutine. NW .LE. LDT */
/* NV (input) integer */
/* The number of rows of work array WV available for */
/* workspace. NV.GE.NW. */
/* WV (workspace) REAL array, dimension (LDWV,NW) */
/* LDWV (input) integer */
/* The leading dimension of W just as declared in the */
/* calling subroutine. NW .LE. LDV */
/* WORK (workspace) REAL array, dimension LWORK. */
/* On exit, WORK(1) is set to an estimate of the optimal value */
/* of LWORK for the given values of N, NW, KTOP and KBOT. */
/* LWORK (input) integer */
/* The dimension of the work array WORK. LWORK = 2*NW */
/* suffices, but greater efficiency may result from larger */
/* values of LWORK. */
/* If LWORK = -1, then a workspace query is assumed; SLAQR2 */
/* only estimates the optimal workspace size for the given */
/* values of N, NW, KTOP and KBOT. The estimate is returned */
/* in WORK(1). No error message related to LWORK is issued */
/* by XERBLA. Neither H nor Z are accessed. */
/* ================================================================ */
/* Based on contributions by */
/* Karen Braman and Ralph Byers, Department of Mathematics, */
/* University of Kansas, USA */
/* ================================================================ */
/* ==== Estimate optimal workspace. ==== */
/* Parameter adjustments */
h_dim1 = *ldh;
h_offset = 1 + h_dim1;
h__ -= h_offset;
z_dim1 = *ldz;
z_offset = 1 + z_dim1;
z__ -= z_offset;
--sr;
--si;
v_dim1 = *ldv;
v_offset = 1 + v_dim1;
v -= v_offset;
t_dim1 = *ldt;
t_offset = 1 + t_dim1;
t -= t_offset;
wv_dim1 = *ldwv;
wv_offset = 1 + wv_dim1;
wv -= wv_offset;
--work;
/* Function Body */
/* Computing MIN */
i__1 = *nw, i__2 = *kbot - *ktop + 1;
jw = min(i__1,i__2);
if (jw <= 2) {
lwkopt = 1;
} else {
/* ==== Workspace query call to SGEHRD ==== */
i__1 = jw - 1;
sgehrd_(&jw, &c__1, &i__1, &t[t_offset], ldt, &work[1], &work[1], &
c_n1, &info);
lwk1 = (integer) work[1];
/* ==== Workspace query call to SORMHR ==== */
i__1 = jw - 1;
sormhr_("R", "N", &jw, &jw, &c__1, &i__1, &t[t_offset], ldt, &work[1],
&v[v_offset], ldv, &work[1], &c_n1, &info);
lwk2 = (integer) work[1];
/* ==== Optimal workspace ==== */
lwkopt = jw + max(lwk1,lwk2);
}
/* ==== Quick return in case of workspace query. ==== */
if (*lwork == -1) {
work[1] = (real) lwkopt;
return 0;
}
*ns = 0;
*nd = 0;
work[1] = 1.f;
if (*ktop > *kbot) {
return 0;
}
if (*nw < 1) {
return 0;
}
/* ==== Machine constants ==== */
safmin = slamch_("SAFE MINIMUM");
safmax = 1.f / safmin;
slabad_(&safmin, &safmax);
ulp = slamch_("PRECISION");
smlnum = safmin * ((real) (*n) / ulp);
/* ==== Setup deflation window ==== */
/* Computing MIN */
i__1 = *nw, i__2 = *kbot - *ktop + 1;
jw = min(i__1,i__2);
kwtop = *kbot - jw + 1;
if (kwtop == *ktop) {
s = 0.f;
} else {
s = h__[kwtop + (kwtop - 1) * h_dim1];
}
if (*kbot == kwtop) {
/* ==== 1-by-1 deflation window: not much to do ==== */
sr[kwtop] = h__[kwtop + kwtop * h_dim1];
si[kwtop] = 0.f;
*ns = 1;
*nd = 0;
/* Computing MAX */
r__2 = smlnum, r__3 = ulp * (r__1 = h__[kwtop + kwtop * h_dim1], dabs(
r__1));
if (dabs(s) <= dmax(r__2,r__3)) {
*ns = 0;
*nd = 1;
if (kwtop > *ktop) {
h__[kwtop + (kwtop - 1) * h_dim1] = 0.f;
}
}
work[1] = 1.f;
return 0;
}
/* ==== Convert to spike-triangular form. (In case of a */
/* . rare QR failure, this routine continues to do */
/* . aggressive early deflation using that part of */
/* . the deflation window that converged using INFQR */
/* . here and there to keep track.) ==== */
slacpy_("U", &jw, &jw, &h__[kwtop + kwtop * h_dim1], ldh, &t[t_offset],
ldt);
i__1 = jw - 1;
i__2 = *ldh + 1;
i__3 = *ldt + 1;
scopy_(&i__1, &h__[kwtop + 1 + kwtop * h_dim1], &i__2, &t[t_dim1 + 2], &
i__3);
slaset_("A", &jw, &jw, &c_b12, &c_b13, &v[v_offset], ldv);
slahqr_(&c_true, &c_true, &jw, &c__1, &jw, &t[t_offset], ldt, &sr[kwtop],
&si[kwtop], &c__1, &jw, &v[v_offset], ldv, &infqr);
/* ==== STREXC needs a clean margin near the diagonal ==== */
i__1 = jw - 3;
for (j = 1; j <= i__1; ++j) {
t[j + 2 + j * t_dim1] = 0.f;
t[j + 3 + j * t_dim1] = 0.f;
}
if (jw > 2) {
t[jw + (jw - 2) * t_dim1] = 0.f;
}
/* ==== Deflation detection loop ==== */
*ns = jw;
ilst = infqr + 1;
L20:
if (ilst <= *ns) {
if (*ns == 1) {
bulge = FALSE_;
} else {
bulge = t[*ns + (*ns - 1) * t_dim1] != 0.f;
}
/* ==== Small spike tip test for deflation ==== */
if (! bulge) {
/* ==== Real eigenvalue ==== */
foo = (r__1 = t[*ns + *ns * t_dim1], dabs(r__1));
if (foo == 0.f) {
foo = dabs(s);
}
/* Computing MAX */
r__2 = smlnum, r__3 = ulp * foo;
if ((r__1 = s * v[*ns * v_dim1 + 1], dabs(r__1)) <= dmax(r__2,
r__3)) {
/* ==== Deflatable ==== */
--(*ns);
} else {
/* ==== Undeflatable. Move it up out of the way. */
/* . (STREXC can not fail in this case.) ==== */
ifst = *ns;
strexc_("V", &jw, &t[t_offset], ldt, &v[v_offset], ldv, &ifst,
&ilst, &work[1], &info);
++ilst;
}
} else {
/* ==== Complex conjugate pair ==== */
foo = (r__3 = t[*ns + *ns * t_dim1], dabs(r__3)) + sqrt((r__1 = t[
*ns + (*ns - 1) * t_dim1], dabs(r__1))) * sqrt((r__2 = t[*
ns - 1 + *ns * t_dim1], dabs(r__2)));
if (foo == 0.f) {
foo = dabs(s);
}
/* Computing MAX */
r__3 = (r__1 = s * v[*ns * v_dim1 + 1], dabs(r__1)), r__4 = (r__2
= s * v[(*ns - 1) * v_dim1 + 1], dabs(r__2));
/* Computing MAX */
r__5 = smlnum, r__6 = ulp * foo;
if (dmax(r__3,r__4) <= dmax(r__5,r__6)) {
/* ==== Deflatable ==== */
*ns += -2;
} else {
/* ==== Undeflatable. Move them up out of the way. */
/* . Fortunately, STREXC does the right thing with */
/* . ILST in case of a rare exchange failure. ==== */
ifst = *ns;
strexc_("V", &jw, &t[t_offset], ldt, &v[v_offset], ldv, &ifst,
&ilst, &work[1], &info);
ilst += 2;
}
}
/* ==== End deflation detection loop ==== */
goto L20;
}
/* ==== Return to Hessenberg form ==== */
if (*ns == 0) {
s = 0.f;
}
if (*ns < jw) {
/* ==== sorting diagonal blocks of T improves accuracy for */
/* . graded matrices. Bubble sort deals well with */
/* . exchange failures. ==== */
sorted = FALSE_;
i__ = *ns + 1;
L30:
if (sorted) {
goto L50;
}
sorted = TRUE_;
kend = i__ - 1;
i__ = infqr + 1;
if (i__ == *ns) {
k = i__ + 1;
} else if (t[i__ + 1 + i__ * t_dim1] == 0.f) {
k = i__ + 1;
} else {
k = i__ + 2;
}
L40:
if (k <= kend) {
if (k == i__ + 1) {
evi = (r__1 = t[i__ + i__ * t_dim1], dabs(r__1));
} else {
evi = (r__3 = t[i__ + i__ * t_dim1], dabs(r__3)) + sqrt((r__1
= t[i__ + 1 + i__ * t_dim1], dabs(r__1))) * sqrt((
r__2 = t[i__ + (i__ + 1) * t_dim1], dabs(r__2)));
}
if (k == kend) {
evk = (r__1 = t[k + k * t_dim1], dabs(r__1));
} else if (t[k + 1 + k * t_dim1] == 0.f) {
evk = (r__1 = t[k + k * t_dim1], dabs(r__1));
} else {
evk = (r__3 = t[k + k * t_dim1], dabs(r__3)) + sqrt((r__1 = t[
k + 1 + k * t_dim1], dabs(r__1))) * sqrt((r__2 = t[k
+ (k + 1) * t_dim1], dabs(r__2)));
}
if (evi >= evk) {
i__ = k;
} else {
sorted = FALSE_;
ifst = i__;
ilst = k;
strexc_("V", &jw, &t[t_offset], ldt, &v[v_offset], ldv, &ifst,
&ilst, &work[1], &info);
if (info == 0) {
i__ = ilst;
} else {
i__ = k;
}
}
if (i__ == kend) {
k = i__ + 1;
} else if (t[i__ + 1 + i__ * t_dim1] == 0.f) {
k = i__ + 1;
} else {
k = i__ + 2;
}
goto L40;
}
goto L30;
L50:
;
}
/* ==== Restore shift/eigenvalue array from T ==== */
i__ = jw;
L60:
if (i__ >= infqr + 1) {
if (i__ == infqr + 1) {
sr[kwtop + i__ - 1] = t[i__ + i__ * t_dim1];
si[kwtop + i__ - 1] = 0.f;
--i__;
} else if (t[i__ + (i__ - 1) * t_dim1] == 0.f) {
sr[kwtop + i__ - 1] = t[i__ + i__ * t_dim1];
si[kwtop + i__ - 1] = 0.f;
--i__;
} else {
aa = t[i__ - 1 + (i__ - 1) * t_dim1];
cc = t[i__ + (i__ - 1) * t_dim1];
bb = t[i__ - 1 + i__ * t_dim1];
dd = t[i__ + i__ * t_dim1];
slanv2_(&aa, &bb, &cc, &dd, &sr[kwtop + i__ - 2], &si[kwtop + i__
- 2], &sr[kwtop + i__ - 1], &si[kwtop + i__ - 1], &cs, &
sn);
i__ += -2;
}
goto L60;
}
if (*ns < jw || s == 0.f) {
if (*ns > 1 && s != 0.f) {
/* ==== Reflect spike back into lower triangle ==== */
scopy_(ns, &v[v_offset], ldv, &work[1], &c__1);
beta = work[1];
slarfg_(ns, &beta, &work[2], &c__1, &tau);
work[1] = 1.f;
i__1 = jw - 2;
i__2 = jw - 2;
slaset_("L", &i__1, &i__2, &c_b12, &c_b12, &t[t_dim1 + 3], ldt);
slarf_("L", ns, &jw, &work[1], &c__1, &tau, &t[t_offset], ldt, &
work[jw + 1]);
slarf_("R", ns, ns, &work[1], &c__1, &tau, &t[t_offset], ldt, &
work[jw + 1]);
slarf_("R", &jw, ns, &work[1], &c__1, &tau, &v[v_offset], ldv, &
work[jw + 1]);
i__1 = *lwork - jw;
sgehrd_(&jw, &c__1, ns, &t[t_offset], ldt, &work[1], &work[jw + 1]
, &i__1, &info);
}
/* ==== Copy updated reduced window into place ==== */
if (kwtop > 1) {
h__[kwtop + (kwtop - 1) * h_dim1] = s * v[v_dim1 + 1];
}
slacpy_("U", &jw, &jw, &t[t_offset], ldt, &h__[kwtop + kwtop * h_dim1]
, ldh);
i__1 = jw - 1;
i__2 = *ldt + 1;
i__3 = *ldh + 1;
scopy_(&i__1, &t[t_dim1 + 2], &i__2, &h__[kwtop + 1 + kwtop * h_dim1],
&i__3);
/* ==== Accumulate orthogonal matrix in order update */
/* . H and Z, if requested. ==== */
if (*ns > 1 && s != 0.f) {
i__1 = *lwork - jw;
sormhr_("R", "N", &jw, ns, &c__1, ns, &t[t_offset], ldt, &work[1],
&v[v_offset], ldv, &work[jw + 1], &i__1, &info);
}
/* ==== Update vertical slab in H ==== */
if (*wantt) {
ltop = 1;
} else {
ltop = *ktop;
}
i__1 = kwtop - 1;
i__2 = *nv;
for (krow = ltop; i__2 < 0 ? krow >= i__1 : krow <= i__1; krow +=
i__2) {
/* Computing MIN */
i__3 = *nv, i__4 = kwtop - krow;
kln = min(i__3,i__4);
sgemm_("N", "N", &kln, &jw, &jw, &c_b13, &h__[krow + kwtop *
h_dim1], ldh, &v[v_offset], ldv, &c_b12, &wv[wv_offset],
ldwv);
slacpy_("A", &kln, &jw, &wv[wv_offset], ldwv, &h__[krow + kwtop *
h_dim1], ldh);
}
/* ==== Update horizontal slab in H ==== */
if (*wantt) {
i__2 = *n;
i__1 = *nh;
for (kcol = *kbot + 1; i__1 < 0 ? kcol >= i__2 : kcol <= i__2;
kcol += i__1) {
/* Computing MIN */
i__3 = *nh, i__4 = *n - kcol + 1;
kln = min(i__3,i__4);
sgemm_("C", "N", &jw, &kln, &jw, &c_b13, &v[v_offset], ldv, &
h__[kwtop + kcol * h_dim1], ldh, &c_b12, &t[t_offset],
ldt);
slacpy_("A", &jw, &kln, &t[t_offset], ldt, &h__[kwtop + kcol *
h_dim1], ldh);
}
}
/* ==== Update vertical slab in Z ==== */
if (*wantz) {
i__1 = *ihiz;
i__2 = *nv;
for (krow = *iloz; i__2 < 0 ? krow >= i__1 : krow <= i__1; krow +=
i__2) {
/* Computing MIN */
i__3 = *nv, i__4 = *ihiz - krow + 1;
kln = min(i__3,i__4);
sgemm_("N", "N", &kln, &jw, &jw, &c_b13, &z__[krow + kwtop *
z_dim1], ldz, &v[v_offset], ldv, &c_b12, &wv[
wv_offset], ldwv);
slacpy_("A", &kln, &jw, &wv[wv_offset], ldwv, &z__[krow +
kwtop * z_dim1], ldz);
}
}
}
*nd = jw - *ns;
/* . INFQR from the spike length takes care */
/* . of the case of a rare QR failure while */
/* . calculating eigenvalues of the deflation */
/* . window.) ==== */
*ns -= infqr;
/* ==== Return optimal workspace. ==== */
work[1] = (real) lwkopt;
/* ==== End of SLAQR2 ==== */
return 0;
} /* slaqr2_ */
/* Subroutine */
int slaqr0_(logical *wantt, logical *wantz, integer *n, integer *ilo, integer *ihi, real *h__, integer *ldh, real *wr, real * wi, integer *iloz, integer *ihiz, real *z__, integer *ldz, real *work, integer *lwork, integer *info)
{
/* System generated locals */
integer h_dim1, h_offset, z_dim1, z_offset, i__1, i__2, i__3, i__4, i__5;
real r__1, r__2, r__3, r__4;
/* Local variables */
integer i__, k;
real aa, bb, cc, dd;
integer ld;
real cs;
integer nh, it, ks, kt;
real sn;
integer ku, kv, ls, ns;
real ss;
integer nw, inf, kdu, nho, nve, kwh, nsr, nwr, kwv, ndec, ndfl, kbot, nmin;
real swap;
integer ktop;
real zdum[1] /* was [1][1] */
;
integer kacc22, itmax, nsmax, nwmax, kwtop;
extern /* Subroutine */
int slanv2_(real *, real *, real *, real *, real * , real *, real *, real *, real *, real *), slaqr3_(logical *, logical *, integer *, integer *, integer *, integer *, real *, integer *, integer *, integer *, real *, integer *, integer *, integer *, real *, real *, real *, integer *, integer *, real *, integer *, integer *, real *, integer *, real *, integer *), slaqr4_(logical *, logical *, integer *, integer *, integer *, real *, integer *, real *, real *, integer *, integer *, real *, integer *, real *, integer *, integer *), slaqr5_(logical *, logical *, integer *, integer *, integer *, integer *, integer *, real *, real *, real *, integer *, integer *, integer *, real *, integer *, real *, integer *, real *, integer *, integer *, real * , integer *, integer *, real *, integer *);
integer nibble;
extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *);
char jbcmpz[2];
extern /* Subroutine */
int slahqr_(logical *, logical *, integer *, integer *, integer *, real *, integer *, real *, real *, integer * , integer *, real *, integer *, integer *), slacpy_(char *, integer *, integer *, real *, integer *, real *, integer *);
integer nwupbd;
logical sorted;
integer lwkopt;
/* -- LAPACK auxiliary routine (version 3.4.2) -- */
/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
/* September 2012 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* ================================================================ */
/* .. Parameters .. */
/* ==== Matrices of order NTINY or smaller must be processed by */
/* . SLAHQR because of insufficient subdiagonal scratch space. */
/* . (This is a hard limit.) ==== */
/* ==== Exceptional deflation windows: try to cure rare */
/* . slow convergence by varying the size of the */
/* . deflation window after KEXNW iterations. ==== */
/* ==== Exceptional shifts: try to cure rare slow convergence */
/* . with ad-hoc exceptional shifts every KEXSH iterations. */
/* . ==== */
/* ==== The constants WILK1 and WILK2 are used to form the */
/* . exceptional shifts. ==== */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. Local Arrays .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Parameter adjustments */
h_dim1 = *ldh;
h_offset = 1 + h_dim1;
h__ -= h_offset;
--wr;
--wi;
z_dim1 = *ldz;
z_offset = 1 + z_dim1;
z__ -= z_offset;
--work;
/* Function Body */
*info = 0;
/* ==== Quick return for N = 0: nothing to do. ==== */
if (*n == 0)
{
work[1] = 1.f;
return 0;
}
if (*n <= 11)
{
/* ==== Tiny matrices must use SLAHQR. ==== */
lwkopt = 1;
if (*lwork != -1)
{
slahqr_(wantt, wantz, n, ilo, ihi, &h__[h_offset], ldh, &wr[1], & wi[1], iloz, ihiz, &z__[z_offset], ldz, info);
}
}
else
{
/* ==== Use small bulge multi-shift QR with aggressive early */
/* . deflation on larger-than-tiny matrices. ==== */
/* ==== Hope for the best. ==== */
*info = 0;
/* ==== Set up job flags for ILAENV. ==== */
if (*wantt)
{
*(unsigned char *)jbcmpz = 'S';
}
else
{
*(unsigned char *)jbcmpz = 'E';
}
if (*wantz)
{
*(unsigned char *)&jbcmpz[1] = 'V';
}
else
{
*(unsigned char *)&jbcmpz[1] = 'N';
}
/* ==== NWR = recommended deflation window size. At this */
/* . point, N .GT. NTINY = 11, so there is enough */
/* . subdiagonal workspace for NWR.GE.2 as required. */
/* . (In fact, there is enough subdiagonal space for */
/* . NWR.GE.3.) ==== */
nwr = ilaenv_(&c__13, "SLAQR0", jbcmpz, n, ilo, ihi, lwork);
nwr = max(2,nwr);
/* Computing MIN */
i__1 = *ihi - *ilo + 1;
i__2 = (*n - 1) / 3;
i__1 = min(i__1,i__2); // ; expr subst
nwr = min(i__1,nwr);
/* ==== NSR = recommended number of simultaneous shifts. */
/* . At this point N .GT. NTINY = 11, so there is at */
/* . enough subdiagonal workspace for NSR to be even */
/* . and greater than or equal to two as required. ==== */
nsr = ilaenv_(&c__15, "SLAQR0", jbcmpz, n, ilo, ihi, lwork);
/* Computing MIN */
i__1 = nsr, i__2 = (*n + 6) / 9;
i__1 = min(i__1,i__2);
i__2 = *ihi - *ilo; // ; expr subst
nsr = min(i__1,i__2);
/* Computing MAX */
i__1 = 2;
i__2 = nsr - nsr % 2; // , expr subst
nsr = max(i__1,i__2);
/* ==== Estimate optimal workspace ==== */
/* ==== Workspace query call to SLAQR3 ==== */
i__1 = nwr + 1;
slaqr3_(wantt, wantz, n, ilo, ihi, &i__1, &h__[h_offset], ldh, iloz, ihiz, &z__[z_offset], ldz, &ls, &ld, &wr[1], &wi[1], &h__[ h_offset], ldh, n, &h__[h_offset], ldh, n, &h__[h_offset], ldh, &work[1], &c_n1);
/* ==== Optimal workspace = MAX(SLAQR5, SLAQR3) ==== */
/* Computing MAX */
i__1 = nsr * 3 / 2;
i__2 = (integer) work[1]; // , expr subst
lwkopt = max(i__1,i__2);
/* ==== Quick return in case of workspace query. ==== */
if (*lwork == -1)
{
work[1] = (real) lwkopt;
return 0;
}
/* ==== SLAHQR/SLAQR0 crossover point ==== */
nmin = ilaenv_(&c__12, "SLAQR0", jbcmpz, n, ilo, ihi, lwork);
nmin = max(11,nmin);
/* ==== Nibble crossover point ==== */
nibble = ilaenv_(&c__14, "SLAQR0", jbcmpz, n, ilo, ihi, lwork);
nibble = max(0,nibble);
/* ==== Accumulate reflections during ttswp? Use block */
/* . 2-by-2 structure during matrix-matrix multiply? ==== */
kacc22 = ilaenv_(&c__16, "SLAQR0", jbcmpz, n, ilo, ihi, lwork);
kacc22 = max(0,kacc22);
kacc22 = min(2,kacc22);
/* ==== NWMAX = the largest possible deflation window for */
/* . which there is sufficient workspace. ==== */
/* Computing MIN */
i__1 = (*n - 1) / 3;
i__2 = *lwork / 2; // , expr subst
nwmax = min(i__1,i__2);
nw = nwmax;
/* ==== NSMAX = the Largest number of simultaneous shifts */
/* . for which there is sufficient workspace. ==== */
/* Computing MIN */
i__1 = (*n + 6) / 9;
i__2 = (*lwork << 1) / 3; // , expr subst
nsmax = min(i__1,i__2);
nsmax -= nsmax % 2;
/* ==== NDFL: an iteration count restarted at deflation. ==== */
ndfl = 1;
/* ==== ITMAX = iteration limit ==== */
/* Computing MAX */
i__1 = 10;
i__2 = *ihi - *ilo + 1; // , expr subst
itmax = max(i__1,i__2) * 30;
/* ==== Last row and column in the active block ==== */
kbot = *ihi;
/* ==== Main Loop ==== */
i__1 = itmax;
for (it = 1;
it <= i__1;
++it)
{
/* ==== Done when KBOT falls below ILO ==== */
if (kbot < *ilo)
{
goto L90;
}
/* ==== Locate active block ==== */
i__2 = *ilo + 1;
for (k = kbot;
k >= i__2;
--k)
{
if (h__[k + (k - 1) * h_dim1] == 0.f)
{
goto L20;
}
/* L10: */
}
k = *ilo;
L20:
ktop = k;
/* ==== Select deflation window size: */
/* . Typical Case: */
/* . If possible and advisable, nibble the entire */
/* . active block. If not, use size MIN(NWR,NWMAX) */
/* . or MIN(NWR+1,NWMAX) depending upon which has */
/* . the smaller corresponding subdiagonal entry */
/* . (a heuristic). */
/* . */
/* . Exceptional Case: */
/* . If there have been no deflations in KEXNW or */
/* . more iterations, then vary the deflation window */
/* . size. At first, because, larger windows are, */
/* . in general, more powerful than smaller ones, */
/* . rapidly increase the window to the maximum possible. */
/* . Then, gradually reduce the window size. ==== */
nh = kbot - ktop + 1;
nwupbd = min(nh,nwmax);
if (ndfl < 5)
{
nw = min(nwupbd,nwr);
}
else
{
/* Computing MIN */
i__2 = nwupbd;
i__3 = nw << 1; // , expr subst
nw = min(i__2,i__3);
}
if (nw < nwmax)
{
if (nw >= nh - 1)
{
nw = nh;
}
else
{
kwtop = kbot - nw + 1;
if ((r__1 = h__[kwtop + (kwtop - 1) * h_dim1], f2c_abs(r__1)) > (r__2 = h__[kwtop - 1 + (kwtop - 2) * h_dim1], f2c_abs(r__2)))
{
++nw;
}
}
}
if (ndfl < 5)
{
ndec = -1;
}
else if (ndec >= 0 || nw >= nwupbd)
{
++ndec;
if (nw - ndec < 2)
{
ndec = 0;
}
nw -= ndec;
}
/* ==== Aggressive early deflation: */
/* . split workspace under the subdiagonal into */
/* . - an nw-by-nw work array V in the lower */
/* . left-hand-corner, */
/* . - an NW-by-at-least-NW-but-more-is-better */
/* . (NW-by-NHO) horizontal work array along */
/* . the bottom edge, */
/* . - an at-least-NW-but-more-is-better (NHV-by-NW) */
/* . vertical work array along the left-hand-edge. */
/* . ==== */
kv = *n - nw + 1;
kt = nw + 1;
nho = *n - nw - 1 - kt + 1;
kwv = nw + 2;
nve = *n - nw - kwv + 1;
/* ==== Aggressive early deflation ==== */
slaqr3_(wantt, wantz, n, &ktop, &kbot, &nw, &h__[h_offset], ldh, iloz, ihiz, &z__[z_offset], ldz, &ls, &ld, &wr[1], &wi[1], &h__[kv + h_dim1], ldh, &nho, &h__[kv + kt * h_dim1], ldh, &nve, &h__[kwv + h_dim1], ldh, &work[1], lwork);
/* ==== Adjust KBOT accounting for new deflations. ==== */
kbot -= ld;
/* ==== KS points to the shifts. ==== */
ks = kbot - ls + 1;
/* ==== Skip an expensive QR sweep if there is a (partly */
/* . heuristic) reason to expect that many eigenvalues */
/* . will deflate without it. Here, the QR sweep is */
/* . skipped if many eigenvalues have just been deflated */
/* . or if the remaining active block is small. */
if (ld == 0 || ld * 100 <= nw * nibble && kbot - ktop + 1 > min( nmin,nwmax))
{
/* ==== NS = nominal number of simultaneous shifts. */
/* . This may be lowered (slightly) if SLAQR3 */
/* . did not provide that many shifts. ==== */
/* Computing MIN */
/* Computing MAX */
i__4 = 2;
i__5 = kbot - ktop; // , expr subst
i__2 = min(nsmax,nsr);
i__3 = max(i__4,i__5); // , expr subst
ns = min(i__2,i__3);
ns -= ns % 2;
/* ==== If there have been no deflations */
/* . in a multiple of KEXSH iterations, */
/* . then try exceptional shifts. */
/* . Otherwise use shifts provided by */
/* . SLAQR3 above or from the eigenvalues */
/* . of a trailing principal submatrix. ==== */
if (ndfl % 6 == 0)
{
ks = kbot - ns + 1;
/* Computing MAX */
i__3 = ks + 1;
i__4 = ktop + 2; // , expr subst
i__2 = max(i__3,i__4);
for (i__ = kbot;
i__ >= i__2;
i__ += -2)
{
ss = (r__1 = h__[i__ + (i__ - 1) * h_dim1], f2c_abs(r__1)) + (r__2 = h__[i__ - 1 + (i__ - 2) * h_dim1], f2c_abs(r__2));
aa = ss * .75f + h__[i__ + i__ * h_dim1];
bb = ss;
cc = ss * -.4375f;
dd = aa;
slanv2_(&aa, &bb, &cc, &dd, &wr[i__ - 1], &wi[i__ - 1] , &wr[i__], &wi[i__], &cs, &sn);
/* L30: */
}
if (ks == ktop)
{
wr[ks + 1] = h__[ks + 1 + (ks + 1) * h_dim1];
wi[ks + 1] = 0.f;
wr[ks] = wr[ks + 1];
wi[ks] = wi[ks + 1];
}
}
else
{
/* ==== Got NS/2 or fewer shifts? Use SLAQR4 or */
/* . SLAHQR on a trailing principal submatrix to */
/* . get more. (Since NS.LE.NSMAX.LE.(N+6)/9, */
/* . there is enough space below the subdiagonal */
/* . to fit an NS-by-NS scratch array.) ==== */
if (kbot - ks + 1 <= ns / 2)
{
ks = kbot - ns + 1;
kt = *n - ns + 1;
slacpy_("A", &ns, &ns, &h__[ks + ks * h_dim1], ldh, & h__[kt + h_dim1], ldh);
if (ns > nmin)
{
slaqr4_(&c_false, &c_false, &ns, &c__1, &ns, &h__[ kt + h_dim1], ldh, &wr[ks], &wi[ks], & c__1, &c__1, zdum, &c__1, &work[1], lwork, &inf);
}
else
{
slahqr_(&c_false, &c_false, &ns, &c__1, &ns, &h__[ kt + h_dim1], ldh, &wr[ks], &wi[ks], & c__1, &c__1, zdum, &c__1, &inf);
}
ks += inf;
/* ==== In case of a rare QR failure use */
/* . eigenvalues of the trailing 2-by-2 */
/* . principal submatrix. ==== */
if (ks >= kbot)
{
aa = h__[kbot - 1 + (kbot - 1) * h_dim1];
cc = h__[kbot + (kbot - 1) * h_dim1];
bb = h__[kbot - 1 + kbot * h_dim1];
dd = h__[kbot + kbot * h_dim1];
slanv2_(&aa, &bb, &cc, &dd, &wr[kbot - 1], &wi[ kbot - 1], &wr[kbot], &wi[kbot], &cs, &sn) ;
ks = kbot - 1;
}
}
if (kbot - ks + 1 > ns)
{
/* ==== Sort the shifts (Helps a little) */
/* . Bubble sort keeps complex conjugate */
/* . pairs together. ==== */
sorted = FALSE_;
i__2 = ks + 1;
for (k = kbot;
k >= i__2;
--k)
{
if (sorted)
{
goto L60;
}
sorted = TRUE_;
i__3 = k - 1;
for (i__ = ks;
i__ <= i__3;
++i__)
{
if ((r__1 = wr[i__], f2c_abs(r__1)) + (r__2 = wi[ i__], f2c_abs(r__2)) < (r__3 = wr[i__ + 1] , f2c_abs(r__3)) + (r__4 = wi[i__ + 1], f2c_abs(r__4)))
{
sorted = FALSE_;
swap = wr[i__];
wr[i__] = wr[i__ + 1];
wr[i__ + 1] = swap;
swap = wi[i__];
wi[i__] = wi[i__ + 1];
wi[i__ + 1] = swap;
}
/* L40: */
}
/* L50: */
}
L60:
;
}
/* ==== Shuffle shifts into pairs of real shifts */
/* . and pairs of complex conjugate shifts */
/* . assuming complex conjugate shifts are */
/* . already adjacent to one another. (Yes, */
/* . they are.) ==== */
i__2 = ks + 2;
for (i__ = kbot;
i__ >= i__2;
i__ += -2)
{
if (wi[i__] != -wi[i__ - 1])
{
swap = wr[i__];
wr[i__] = wr[i__ - 1];
wr[i__ - 1] = wr[i__ - 2];
wr[i__ - 2] = swap;
swap = wi[i__];
wi[i__] = wi[i__ - 1];
wi[i__ - 1] = wi[i__ - 2];
wi[i__ - 2] = swap;
}
/* L70: */
}
}
/* ==== If there are only two shifts and both are */
/* . real, then use only one. ==== */
if (kbot - ks + 1 == 2)
{
if (wi[kbot] == 0.f)
{
if ((r__1 = wr[kbot] - h__[kbot + kbot * h_dim1], f2c_abs( r__1)) < (r__2 = wr[kbot - 1] - h__[kbot + kbot * h_dim1], f2c_abs(r__2)))
{
wr[kbot - 1] = wr[kbot];
}
else
{
wr[kbot] = wr[kbot - 1];
}
}
}
/* ==== Use up to NS of the the smallest magnatiude */
/* . shifts. If there aren't NS shifts available, */
/* . then use them all, possibly dropping one to */
/* . make the number of shifts even. ==== */
/* Computing MIN */
i__2 = ns;
i__3 = kbot - ks + 1; // , expr subst
ns = min(i__2,i__3);
ns -= ns % 2;
ks = kbot - ns + 1;
/* ==== Small-bulge multi-shift QR sweep: */
/* . split workspace under the subdiagonal into */
/* . - a KDU-by-KDU work array U in the lower */
/* . left-hand-corner, */
/* . - a KDU-by-at-least-KDU-but-more-is-better */
/* . (KDU-by-NHo) horizontal work array WH along */
/* . the bottom edge, */
/* . - and an at-least-KDU-but-more-is-better-by-KDU */
/* . (NVE-by-KDU) vertical work WV arrow along */
/* . the left-hand-edge. ==== */
kdu = ns * 3 - 3;
ku = *n - kdu + 1;
kwh = kdu + 1;
nho = *n - kdu - 3 - (kdu + 1) + 1;
kwv = kdu + 4;
nve = *n - kdu - kwv + 1;
/* ==== Small-bulge multi-shift QR sweep ==== */
slaqr5_(wantt, wantz, &kacc22, n, &ktop, &kbot, &ns, &wr[ks], &wi[ks], &h__[h_offset], ldh, iloz, ihiz, &z__[ z_offset], ldz, &work[1], &c__3, &h__[ku + h_dim1], ldh, &nve, &h__[kwv + h_dim1], ldh, &nho, &h__[ku + kwh * h_dim1], ldh);
}
/* ==== Note progress (or the lack of it). ==== */
if (ld > 0)
{
ndfl = 1;
}
else
{
++ndfl;
}
/* ==== End of main loop ==== */
/* L80: */
}
/* ==== Iteration limit exceeded. Set INFO to show where */
/* . the problem occurred and exit. ==== */
*info = kbot;
L90:
;
}
/* ==== Return the optimal value of LWORK. ==== */
work[1] = (real) lwkopt;
/* ==== End of SLAQR0 ==== */
return 0;
}
/* Subroutine */ int shseqr_(char *job, char *compz, integer *n, integer *ilo,
integer *ihi, real *h__, integer *ldh, real *wr, real *wi, real *z__,
integer *ldz, real *work, integer *lwork, integer *info, ftnlen
job_len, ftnlen compz_len)
{
/* System generated locals */
address a__1[2];
integer h_dim1, h_offset, z_dim1, z_offset, i__1, i__2, i__3[2], i__4,
i__5;
real r__1, r__2;
char ch__1[2];
/* Builtin functions */
/* Subroutine */ int s_cat(char *, char **, integer *, integer *, ftnlen);
/* Local variables */
static integer i__, j, k, l;
static real s[225] /* was [15][15] */, v[16];
static integer i1, i2, ii, nh, nr, ns, nv;
static real vv[16];
static integer itn;
static real tau;
static integer its;
static real ulp, tst1;
static integer maxb;
static real absw;
static integer ierr;
static real unfl, temp, ovfl;
extern logical lsame_(char *, char *, ftnlen, ftnlen);
extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *);
static integer itemp;
extern /* Subroutine */ int sgemv_(char *, integer *, integer *, real *,
real *, integer *, real *, integer *, real *, real *, integer *,
ftnlen);
static logical initz, wantt;
extern /* Subroutine */ int scopy_(integer *, real *, integer *, real *,
integer *);
static logical wantz;
extern doublereal slapy2_(real *, real *);
extern /* Subroutine */ int slabad_(real *, real *);
extern doublereal slamch_(char *, ftnlen);
extern /* Subroutine */ int xerbla_(char *, integer *, ftnlen);
extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
integer *, integer *, ftnlen, ftnlen);
extern /* Subroutine */ int slarfg_(integer *, real *, real *, integer *,
real *);
extern integer isamax_(integer *, real *, integer *);
extern doublereal slanhs_(char *, integer *, real *, integer *, real *,
ftnlen);
extern /* Subroutine */ int slahqr_(logical *, logical *, integer *,
integer *, integer *, real *, integer *, real *, real *, integer *
, integer *, real *, integer *, integer *), slacpy_(char *,
integer *, integer *, real *, integer *, real *, integer *,
ftnlen), slaset_(char *, integer *, integer *, real *, real *,
real *, integer *, ftnlen), slarfx_(char *, integer *, integer *,
real *, real *, real *, integer *, real *, ftnlen);
static real smlnum;
static logical lquery;
/* -- LAPACK routine (version 3.0) -- */
/* Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd., */
/* Courant Institute, Argonne National Lab, and Rice University */
/* June 30, 1999 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* SHSEQR computes the eigenvalues of a real upper Hessenberg matrix H */
/* and, optionally, the matrices T and Z from the Schur decomposition */
/* H = Z T Z**T, where T is an upper quasi-triangular matrix (the Schur */
/* form), and Z is the orthogonal matrix of Schur vectors. */
/* Optionally Z may be postmultiplied into an input orthogonal matrix Q, */
/* so that this routine can give the Schur factorization of a matrix A */
/* which has been reduced to the Hessenberg form H by the orthogonal */
/* matrix Q: A = Q*H*Q**T = (QZ)*T*(QZ)**T. */
/* Arguments */
/* ========= */
/* JOB (input) CHARACTER*1 */
/* = 'E': compute eigenvalues only; */
/* = 'S': compute eigenvalues and the Schur form T. */
/* COMPZ (input) CHARACTER*1 */
/* = 'N': no Schur vectors are computed; */
/* = 'I': Z is initialized to the unit matrix and the matrix Z */
/* of Schur vectors of H is returned; */
/* = 'V': Z must contain an orthogonal matrix Q on entry, and */
/* the product Q*Z is returned. */
/* N (input) INTEGER */
/* The order of the matrix H. N >= 0. */
/* ILO (input) INTEGER */
/* IHI (input) INTEGER */
/* It is assumed that H is already upper triangular in rows */
/* and columns 1:ILO-1 and IHI+1:N. ILO and IHI are normally */
/* set by a previous call to SGEBAL, and then passed to SGEHRD */
/* when the matrix output by SGEBAL is reduced to Hessenberg */
/* form. Otherwise ILO and IHI should be set to 1 and N */
/* respectively. */
/* 1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0. */
/* H (input/output) REAL array, dimension (LDH,N) */
/* On entry, the upper Hessenberg matrix H. */
/* On exit, if JOB = 'S', H contains the upper quasi-triangular */
/* matrix T from the Schur decomposition (the Schur form); */
/* 2-by-2 diagonal blocks (corresponding to complex conjugate */
/* pairs of eigenvalues) are returned in standard form, with */
/* H(i,i) = H(i+1,i+1) and H(i+1,i)*H(i,i+1) < 0. If JOB = 'E', */
/* the contents of H are unspecified on exit. */
/* LDH (input) INTEGER */
/* The leading dimension of the array H. LDH >= max(1,N). */
/* WR (output) REAL array, dimension (N) */
/* WI (output) REAL array, dimension (N) */
/* The real and imaginary parts, respectively, of the computed */
/* eigenvalues. If two eigenvalues are computed as a complex */
/* conjugate pair, they are stored in consecutive elements of */
/* WR and WI, say the i-th and (i+1)th, with WI(i) > 0 and */
/* WI(i+1) < 0. If JOB = 'S', the eigenvalues are stored in the */
/* same order as on the diagonal of the Schur form returned in */
/* H, with WR(i) = H(i,i) and, if H(i:i+1,i:i+1) is a 2-by-2 */
/* diagonal block, WI(i) = sqrt(H(i+1,i)*H(i,i+1)) and */
/* WI(i+1) = -WI(i). */
/* Z (input/output) REAL array, dimension (LDZ,N) */
/* If COMPZ = 'N': Z is not referenced. */
/* If COMPZ = 'I': on entry, Z need not be set, and on exit, Z */
/* contains the orthogonal matrix Z of the Schur vectors of H. */
/* If COMPZ = 'V': on entry Z must contain an N-by-N matrix Q, */
/* which is assumed to be equal to the unit matrix except for */
/* the submatrix Z(ILO:IHI,ILO:IHI); on exit Z contains Q*Z. */
/* Normally Q is the orthogonal matrix generated by SORGHR after */
/* the call to SGEHRD which formed the Hessenberg matrix H. */
/* LDZ (input) INTEGER */
/* The leading dimension of the array Z. */
/* LDZ >= max(1,N) if COMPZ = 'I' or 'V'; LDZ >= 1 otherwise. */
/* WORK (workspace/output) REAL array, dimension (LWORK) */
/* On exit, if INFO = 0, WORK(1) returns the optimal LWORK. */
/* LWORK (input) INTEGER */
/* The dimension of the array WORK. LWORK >= max(1,N). */
/* If LWORK = -1, then a workspace query is assumed; the routine */
/* only calculates the optimal size of the WORK array, returns */
/* this value as the first entry of the WORK array, and no error */
/* message related to LWORK is issued by XERBLA. */
/* INFO (output) INTEGER */
/* = 0: successful exit */
/* < 0: if INFO = -i, the i-th argument had an illegal value */
/* > 0: if INFO = i, SHSEQR failed to compute all of the */
/* eigenvalues in a total of 30*(IHI-ILO+1) iterations; */
/* elements 1:ilo-1 and i+1:n of WR and WI contain those */
/* eigenvalues which have been successfully computed. */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. Local Arrays .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Decode and test the input parameters */
/* Parameter adjustments */
h_dim1 = *ldh;
h_offset = 1 + h_dim1;
h__ -= h_offset;
--wr;
--wi;
z_dim1 = *ldz;
z_offset = 1 + z_dim1;
z__ -= z_offset;
--work;
/* Function Body */
wantt = lsame_(job, "S", (ftnlen)1, (ftnlen)1);
initz = lsame_(compz, "I", (ftnlen)1, (ftnlen)1);
wantz = initz || lsame_(compz, "V", (ftnlen)1, (ftnlen)1);
*info = 0;
work[1] = (real) max(1,*n);
lquery = *lwork == -1;
if (! lsame_(job, "E", (ftnlen)1, (ftnlen)1) && ! wantt) {
*info = -1;
} else if (! lsame_(compz, "N", (ftnlen)1, (ftnlen)1) && ! wantz) {
*info = -2;
} else if (*n < 0) {
*info = -3;
} else if (*ilo < 1 || *ilo > max(1,*n)) {
*info = -4;
} else if (*ihi < min(*ilo,*n) || *ihi > *n) {
*info = -5;
} else if (*ldh < max(1,*n)) {
*info = -7;
} else if (*ldz < 1 || wantz && *ldz < max(1,*n)) {
*info = -11;
} else if (*lwork < max(1,*n) && ! lquery) {
*info = -13;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("SHSEQR", &i__1, (ftnlen)6);
return 0;
} else if (lquery) {
return 0;
}
/* Initialize Z, if necessary */
if (initz) {
slaset_("Full", n, n, &c_b9, &c_b10, &z__[z_offset], ldz, (ftnlen)4);
}
/* Store the eigenvalues isolated by SGEBAL. */
i__1 = *ilo - 1;
for (i__ = 1; i__ <= i__1; ++i__) {
wr[i__] = h__[i__ + i__ * h_dim1];
wi[i__] = 0.f;
/* L10: */
}
i__1 = *n;
for (i__ = *ihi + 1; i__ <= i__1; ++i__) {
wr[i__] = h__[i__ + i__ * h_dim1];
wi[i__] = 0.f;
/* L20: */
}
/* Quick return if possible. */
if (*n == 0) {
return 0;
}
if (*ilo == *ihi) {
wr[*ilo] = h__[*ilo + *ilo * h_dim1];
wi[*ilo] = 0.f;
return 0;
}
/* Set rows and columns ILO to IHI to zero below the first */
/* subdiagonal. */
i__1 = *ihi - 2;
for (j = *ilo; j <= i__1; ++j) {
i__2 = *n;
for (i__ = j + 2; i__ <= i__2; ++i__) {
h__[i__ + j * h_dim1] = 0.f;
/* L30: */
}
/* L40: */
}
nh = *ihi - *ilo + 1;
/* Determine the order of the multi-shift QR algorithm to be used. */
/* Writing concatenation */
i__3[0] = 1, a__1[0] = job;
i__3[1] = 1, a__1[1] = compz;
s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2);
ns = ilaenv_(&c__4, "SHSEQR", ch__1, n, ilo, ihi, &c_n1, (ftnlen)6, (
ftnlen)2);
/* Writing concatenation */
i__3[0] = 1, a__1[0] = job;
i__3[1] = 1, a__1[1] = compz;
s_cat(ch__1, a__1, i__3, &c__2, (ftnlen)2);
maxb = ilaenv_(&c__8, "SHSEQR", ch__1, n, ilo, ihi, &c_n1, (ftnlen)6, (
ftnlen)2);
if (ns <= 2 || ns > nh || maxb >= nh) {
/* Use the standard double-shift algorithm */
slahqr_(&wantt, &wantz, n, ilo, ihi, &h__[h_offset], ldh, &wr[1], &wi[
1], ilo, ihi, &z__[z_offset], ldz, info);
return 0;
}
maxb = max(3,maxb);
/* Computing MIN */
i__1 = min(ns,maxb);
ns = min(i__1,15);
/* Now 2 < NS <= MAXB < NH. */
/* Set machine-dependent constants for the stopping criterion. */
/* If norm(H) <= sqrt(OVFL), overflow should not occur. */
unfl = slamch_("Safe minimum", (ftnlen)12);
ovfl = 1.f / unfl;
slabad_(&unfl, &ovfl);
ulp = slamch_("Precision", (ftnlen)9);
smlnum = unfl * (nh / ulp);
/* I1 and I2 are the indices of the first row and last column of H */
/* to which transformations must be applied. If eigenvalues only are */
/* being computed, I1 and I2 are set inside the main loop. */
if (wantt) {
i1 = 1;
i2 = *n;
}
/* ITN is the total number of multiple-shift QR iterations allowed. */
itn = nh * 30;
/* The main loop begins here. I is the loop index and decreases from */
/* IHI to ILO in steps of at most MAXB. Each iteration of the loop */
/* works with the active submatrix in rows and columns L to I. */
/* Eigenvalues I+1 to IHI have already converged. Either L = ILO or */
/* H(L,L-1) is negligible so that the matrix splits. */
i__ = *ihi;
L50:
l = *ilo;
if (i__ < *ilo) {
goto L170;
}
/* Perform multiple-shift QR iterations on rows and columns ILO to I */
/* until a submatrix of order at most MAXB splits off at the bottom */
/* because a subdiagonal element has become negligible. */
i__1 = itn;
for (its = 0; its <= i__1; ++its) {
/* Look for a single small subdiagonal element. */
i__2 = l + 1;
for (k = i__; k >= i__2; --k) {
tst1 = (r__1 = h__[k - 1 + (k - 1) * h_dim1], dabs(r__1)) + (r__2
= h__[k + k * h_dim1], dabs(r__2));
if (tst1 == 0.f) {
i__4 = i__ - l + 1;
tst1 = slanhs_("1", &i__4, &h__[l + l * h_dim1], ldh, &work[1]
, (ftnlen)1);
}
/* Computing MAX */
r__2 = ulp * tst1;
if ((r__1 = h__[k + (k - 1) * h_dim1], dabs(r__1)) <= dmax(r__2,
smlnum)) {
goto L70;
}
/* L60: */
}
L70:
l = k;
if (l > *ilo) {
/* H(L,L-1) is negligible. */
h__[l + (l - 1) * h_dim1] = 0.f;
}
/* Exit from loop if a submatrix of order <= MAXB has split off. */
if (l >= i__ - maxb + 1) {
goto L160;
}
/* Now the active submatrix is in rows and columns L to I. If */
/* eigenvalues only are being computed, only the active submatrix */
/* need be transformed. */
if (! wantt) {
i1 = l;
i2 = i__;
}
if (its == 20 || its == 30) {
/* Exceptional shifts. */
i__2 = i__;
for (ii = i__ - ns + 1; ii <= i__2; ++ii) {
wr[ii] = ((r__1 = h__[ii + (ii - 1) * h_dim1], dabs(r__1)) + (
r__2 = h__[ii + ii * h_dim1], dabs(r__2))) * 1.5f;
wi[ii] = 0.f;
/* L80: */
}
} else {
/* Use eigenvalues of trailing submatrix of order NS as shifts. */
slacpy_("Full", &ns, &ns, &h__[i__ - ns + 1 + (i__ - ns + 1) *
h_dim1], ldh, s, &c__15, (ftnlen)4);
slahqr_(&c_false, &c_false, &ns, &c__1, &ns, s, &c__15, &wr[i__ -
ns + 1], &wi[i__ - ns + 1], &c__1, &ns, &z__[z_offset],
ldz, &ierr);
if (ierr > 0) {
/* If SLAHQR failed to compute all NS eigenvalues, use the */
/* unconverged diagonal elements as the remaining shifts. */
i__2 = ierr;
for (ii = 1; ii <= i__2; ++ii) {
wr[i__ - ns + ii] = s[ii + ii * 15 - 16];
wi[i__ - ns + ii] = 0.f;
/* L90: */
}
}
}
/* Form the first column of (G-w(1)) (G-w(2)) . . . (G-w(ns)) */
/* where G is the Hessenberg submatrix H(L:I,L:I) and w is */
/* the vector of shifts (stored in WR and WI). The result is */
/* stored in the local array V. */
v[0] = 1.f;
i__2 = ns + 1;
for (ii = 2; ii <= i__2; ++ii) {
v[ii - 1] = 0.f;
/* L100: */
}
nv = 1;
i__2 = i__;
for (j = i__ - ns + 1; j <= i__2; ++j) {
if (wi[j] >= 0.f) {
if (wi[j] == 0.f) {
/* real shift */
i__4 = nv + 1;
scopy_(&i__4, v, &c__1, vv, &c__1);
i__4 = nv + 1;
r__1 = -wr[j];
sgemv_("No transpose", &i__4, &nv, &c_b10, &h__[l + l *
h_dim1], ldh, vv, &c__1, &r__1, v, &c__1, (ftnlen)
12);
++nv;
} else if (wi[j] > 0.f) {
/* complex conjugate pair of shifts */
i__4 = nv + 1;
scopy_(&i__4, v, &c__1, vv, &c__1);
i__4 = nv + 1;
r__1 = wr[j] * -2.f;
sgemv_("No transpose", &i__4, &nv, &c_b10, &h__[l + l *
h_dim1], ldh, v, &c__1, &r__1, vv, &c__1, (ftnlen)
12);
i__4 = nv + 1;
itemp = isamax_(&i__4, vv, &c__1);
/* Computing MAX */
r__2 = (r__1 = vv[itemp - 1], dabs(r__1));
temp = 1.f / dmax(r__2,smlnum);
i__4 = nv + 1;
sscal_(&i__4, &temp, vv, &c__1);
absw = slapy2_(&wr[j], &wi[j]);
temp = temp * absw * absw;
i__4 = nv + 2;
i__5 = nv + 1;
sgemv_("No transpose", &i__4, &i__5, &c_b10, &h__[l + l *
h_dim1], ldh, vv, &c__1, &temp, v, &c__1, (ftnlen)
12);
nv += 2;
}
/* Scale V(1:NV) so that max(abs(V(i))) = 1. If V is zero, */
/* reset it to the unit vector. */
itemp = isamax_(&nv, v, &c__1);
temp = (r__1 = v[itemp - 1], dabs(r__1));
if (temp == 0.f) {
v[0] = 1.f;
i__4 = nv;
for (ii = 2; ii <= i__4; ++ii) {
v[ii - 1] = 0.f;
/* L110: */
}
} else {
temp = dmax(temp,smlnum);
r__1 = 1.f / temp;
sscal_(&nv, &r__1, v, &c__1);
}
}
/* L120: */
}
/* Multiple-shift QR step */
i__2 = i__ - 1;
for (k = l; k <= i__2; ++k) {
/* The first iteration of this loop determines a reflection G */
/* from the vector V and applies it from left and right to H, */
/* thus creating a nonzero bulge below the subdiagonal. */
/* Each subsequent iteration determines a reflection G to */
/* restore the Hessenberg form in the (K-1)th column, and thus */
/* chases the bulge one step toward the bottom of the active */
/* submatrix. NR is the order of G. */
/* Computing MIN */
i__4 = ns + 1, i__5 = i__ - k + 1;
nr = min(i__4,i__5);
if (k > l) {
scopy_(&nr, &h__[k + (k - 1) * h_dim1], &c__1, v, &c__1);
}
slarfg_(&nr, v, &v[1], &c__1, &tau);
if (k > l) {
h__[k + (k - 1) * h_dim1] = v[0];
i__4 = i__;
for (ii = k + 1; ii <= i__4; ++ii) {
h__[ii + (k - 1) * h_dim1] = 0.f;
/* L130: */
}
}
v[0] = 1.f;
/* Apply G from the left to transform the rows of the matrix in */
/* columns K to I2. */
i__4 = i2 - k + 1;
slarfx_("Left", &nr, &i__4, v, &tau, &h__[k + k * h_dim1], ldh, &
work[1], (ftnlen)4);
/* Apply G from the right to transform the columns of the */
/* matrix in rows I1 to min(K+NR,I). */
/* Computing MIN */
i__5 = k + nr;
i__4 = min(i__5,i__) - i1 + 1;
slarfx_("Right", &i__4, &nr, v, &tau, &h__[i1 + k * h_dim1], ldh,
&work[1], (ftnlen)5);
if (wantz) {
/* Accumulate transformations in the matrix Z */
slarfx_("Right", &nh, &nr, v, &tau, &z__[*ilo + k * z_dim1],
ldz, &work[1], (ftnlen)5);
}
/* L140: */
}
/* L150: */
}
/* Failure to converge in remaining number of iterations */
*info = i__;
return 0;
L160:
/* A submatrix of order <= MAXB in rows and columns L to I has split */
/* off. Use the double-shift QR algorithm to handle it. */
slahqr_(&wantt, &wantz, n, &l, &i__, &h__[h_offset], ldh, &wr[1], &wi[1],
ilo, ihi, &z__[z_offset], ldz, info);
if (*info > 0) {
return 0;
}
/* Decrement number of remaining iterations, and return to start of */
/* the main loop with a new value of I. */
itn -= its;
i__ = l - 1;
goto L50;
L170:
work[1] = (real) max(1,*n);
return 0;
/* End of SHSEQR */
} /* shseqr_ */
/* Subroutine */ int shseqr_(char *job, char *compz, integer *n, integer *ilo,
integer *ihi, real *h__, integer *ldh, real *wr, real *wi, real *z__,
integer *ldz, real *work, integer *lwork, integer *info)
{
/* System generated locals */
address a__1[2];
integer h_dim1, h_offset, z_dim1, z_offset, i__1, i__2[2], i__3;
real r__1;
char ch__1[2];
/* Builtin functions */
/* Subroutine */ int s_cat(char *, char **, integer *, integer *, ftnlen);
/* Local variables */
integer i__;
#ifdef LAPACK_DISABLE_MEMORY_HOGS
real hl[1] /* was [49][49] */;
/** This function uses too much memory, so we stopped allocating the memory
* above and assert false here. */
assert(0 && "shseqr_ was called. This function allocates too much"
" memory and has been disabled.");
#else
real hl[2401] /* was [49][49] */;
#endif
integer kbot, nmin;
extern logical lsame_(char *, char *);
logical initz;
real workl[49];
logical wantt, wantz;
extern /* Subroutine */ int slaqr0_(logical *, logical *, integer *,
integer *, integer *, real *, integer *, real *, real *, integer *
, integer *, real *, integer *, real *, integer *, integer *),
xerbla_(char *, integer *);
extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
integer *, integer *);
extern /* Subroutine */ int slahqr_(logical *, logical *, integer *,
integer *, integer *, real *, integer *, real *, real *, integer *
, integer *, real *, integer *, integer *), slacpy_(char *,
integer *, integer *, real *, integer *, real *, integer *), slaset_(char *, integer *, integer *, real *, real *,
real *, integer *);
logical lquery;
/* -- LAPACK driver routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* SHSEQR computes the eigenvalues of a Hessenberg matrix H */
/* and, optionally, the matrices T and Z from the Schur decomposition */
/* H = Z T Z**T, where T is an upper quasi-triangular matrix (the */
/* Schur form), and Z is the orthogonal matrix of Schur vectors. */
/* Optionally Z may be postmultiplied into an input orthogonal */
/* matrix Q so that this routine can give the Schur factorization */
/* of a matrix A which has been reduced to the Hessenberg form H */
/* by the orthogonal matrix Q: A = Q*H*Q**T = (QZ)*T*(QZ)**T. */
/* Arguments */
/* ========= */
/* JOB (input) CHARACTER*1 */
/* = 'E': compute eigenvalues only; */
/* = 'S': compute eigenvalues and the Schur form T. */
/* COMPZ (input) CHARACTER*1 */
/* = 'N': no Schur vectors are computed; */
/* = 'I': Z is initialized to the unit matrix and the matrix Z */
/* of Schur vectors of H is returned; */
/* = 'V': Z must contain an orthogonal matrix Q on entry, and */
/* the product Q*Z is returned. */
/* N (input) INTEGER */
/* The order of the matrix H. N .GE. 0. */
/* ILO (input) INTEGER */
/* IHI (input) INTEGER */
/* It is assumed that H is already upper triangular in rows */
/* and columns 1:ILO-1 and IHI+1:N. ILO and IHI are normally */
/* set by a previous call to SGEBAL, and then passed to SGEHRD */
/* when the matrix output by SGEBAL is reduced to Hessenberg */
/* form. Otherwise ILO and IHI should be set to 1 and N */
/* respectively. If N.GT.0, then 1.LE.ILO.LE.IHI.LE.N. */
/* If N = 0, then ILO = 1 and IHI = 0. */
/* H (input/output) REAL array, dimension (LDH,N) */
/* On entry, the upper Hessenberg matrix H. */
/* On exit, if INFO = 0 and JOB = 'S', then H contains the */
/* upper quasi-triangular matrix T from the Schur decomposition */
/* (the Schur form); 2-by-2 diagonal blocks (corresponding to */
/* complex conjugate pairs of eigenvalues) are returned in */
/* standard form, with H(i,i) = H(i+1,i+1) and */
/* H(i+1,i)*H(i,i+1).LT.0. If INFO = 0 and JOB = 'E', the */
/* contents of H are unspecified on exit. (The output value of */
/* H when INFO.GT.0 is given under the description of INFO */
/* below.) */
/* Unlike earlier versions of SHSEQR, this subroutine may */
/* explicitly H(i,j) = 0 for i.GT.j and j = 1, 2, ... ILO-1 */
/* or j = IHI+1, IHI+2, ... N. */
/* LDH (input) INTEGER */
/* The leading dimension of the array H. LDH .GE. max(1,N). */
/* WR (output) REAL array, dimension (N) */
/* WI (output) REAL array, dimension (N) */
/* The real and imaginary parts, respectively, of the computed */
/* eigenvalues. If two eigenvalues are computed as a complex */
/* conjugate pair, they are stored in consecutive elements of */
/* WR and WI, say the i-th and (i+1)th, with WI(i) .GT. 0 and */
/* WI(i+1) .LT. 0. If JOB = 'S', the eigenvalues are stored in */
/* the same order as on the diagonal of the Schur form returned */
/* in H, with WR(i) = H(i,i) and, if H(i:i+1,i:i+1) is a 2-by-2 */
/* diagonal block, WI(i) = sqrt(-H(i+1,i)*H(i,i+1)) and */
/* WI(i+1) = -WI(i). */
/* Z (input/output) REAL array, dimension (LDZ,N) */
/* If COMPZ = 'N', Z is not referenced. */
/* If COMPZ = 'I', on entry Z need not be set and on exit, */
/* if INFO = 0, Z contains the orthogonal matrix Z of the Schur */
/* vectors of H. If COMPZ = 'V', on entry Z must contain an */
/* N-by-N matrix Q, which is assumed to be equal to the unit */
/* matrix except for the submatrix Z(ILO:IHI,ILO:IHI). On exit, */
/* if INFO = 0, Z contains Q*Z. */
/* Normally Q is the orthogonal matrix generated by SORGHR */
/* after the call to SGEHRD which formed the Hessenberg matrix */
/* H. (The output value of Z when INFO.GT.0 is given under */
/* the description of INFO below.) */
/* LDZ (input) INTEGER */
/* The leading dimension of the array Z. if COMPZ = 'I' or */
/* COMPZ = 'V', then LDZ.GE.MAX(1,N). Otherwize, LDZ.GE.1. */
/* WORK (workspace/output) REAL array, dimension (LWORK) */
/* On exit, if INFO = 0, WORK(1) returns an estimate of */
/* the optimal value for LWORK. */
/* LWORK (input) INTEGER */
/* The dimension of the array WORK. LWORK .GE. max(1,N) */
/* is sufficient and delivers very good and sometimes */
/* optimal performance. However, LWORK as large as 11*N */
/* may be required for optimal performance. A workspace */
/* query is recommended to determine the optimal workspace */
/* size. */
/* If LWORK = -1, then SHSEQR does a workspace query. */
/* In this case, SHSEQR checks the input parameters and */
/* estimates the optimal workspace size for the given */
/* values of N, ILO and IHI. The estimate is returned */
/* in WORK(1). No error message related to LWORK is */
/* issued by XERBLA. Neither H nor Z are accessed. */
/* INFO (output) INTEGER */
/* = 0: successful exit */
/* .LT. 0: if INFO = -i, the i-th argument had an illegal */
/* value */
/* .GT. 0: if INFO = i, SHSEQR failed to compute all of */
/* the eigenvalues. Elements 1:ilo-1 and i+1:n of WR */
/* and WI contain those eigenvalues which have been */
/* successfully computed. (Failures are rare.) */
/* If INFO .GT. 0 and JOB = 'E', then on exit, the */
/* remaining unconverged eigenvalues are the eigen- */
/* values of the upper Hessenberg matrix rows and */
/* columns ILO through INFO of the final, output */
/* value of H. */
/* If INFO .GT. 0 and JOB = 'S', then on exit */
/* (*) (initial value of H)*U = U*(final value of H) */
/* where U is an orthogonal matrix. The final */
/* value of H is upper Hessenberg and quasi-triangular */
/* in rows and columns INFO+1 through IHI. */
/* If INFO .GT. 0 and COMPZ = 'V', then on exit */
/* (final value of Z) = (initial value of Z)*U */
/* where U is the orthogonal matrix in (*) (regard- */
/* less of the value of JOB.) */
/* If INFO .GT. 0 and COMPZ = 'I', then on exit */
/* (final value of Z) = U */
/* where U is the orthogonal matrix in (*) (regard- */
/* less of the value of JOB.) */
/* If INFO .GT. 0 and COMPZ = 'N', then Z is not */
/* accessed. */
/* ================================================================ */
/* Default values supplied by */
/* ILAENV(ISPEC,'SHSEQR',JOB(:1)//COMPZ(:1),N,ILO,IHI,LWORK). */
/* It is suggested that these defaults be adjusted in order */
/* to attain best performance in each particular */
/* computational environment. */
/* ISPEC=12: The SLAHQR vs SLAQR0 crossover point. */
/* Default: 75. (Must be at least 11.) */
/* ISPEC=13: Recommended deflation window size. */
/* This depends on ILO, IHI and NS. NS is the */
/* number of simultaneous shifts returned */
/* by ILAENV(ISPEC=15). (See ISPEC=15 below.) */
/* The default for (IHI-ILO+1).LE.500 is NS. */
/* The default for (IHI-ILO+1).GT.500 is 3*NS/2. */
/* ISPEC=14: Nibble crossover point. (See IPARMQ for */
/* details.) Default: 14% of deflation window */
/* size. */
/* ISPEC=15: Number of simultaneous shifts in a multishift */
/* QR iteration. */
/* If IHI-ILO+1 is ... */
/* greater than ...but less ... the */
/* or equal to ... than default is */
/* 1 30 NS = 2(+) */
/* 30 60 NS = 4(+) */
/* 60 150 NS = 10(+) */
/* 150 590 NS = ** */
/* 590 3000 NS = 64 */
/* 3000 6000 NS = 128 */
/* 6000 infinity NS = 256 */
/* (+) By default some or all matrices of this order */
/* are passed to the implicit double shift routine */
/* SLAHQR and this parameter is ignored. See */
/* ISPEC=12 above and comments in IPARMQ for */
/* details. */
/* (**) The asterisks (**) indicate an ad-hoc */
/* function of N increasing from 10 to 64. */
/* ISPEC=16: Select structured matrix multiply. */
/* If the number of simultaneous shifts (specified */
/* by ISPEC=15) is less than 14, then the default */
/* for ISPEC=16 is 0. Otherwise the default for */
/* ISPEC=16 is 2. */
/* ================================================================ */
/* Based on contributions by */
/* Karen Braman and Ralph Byers, Department of Mathematics, */
/* University of Kansas, USA */
/* ================================================================ */
/* References: */
/* K. Braman, R. Byers and R. Mathias, The Multi-Shift QR */
/* Algorithm Part I: Maintaining Well Focused Shifts, and Level 3 */
/* Performance, SIAM Journal of Matrix Analysis, volume 23, pages */
/* 929--947, 2002. */
/* K. Braman, R. Byers and R. Mathias, The Multi-Shift QR */
/* Algorithm Part II: Aggressive Early Deflation, SIAM Journal */
/* of Matrix Analysis, volume 23, pages 948--973, 2002. */
/* ================================================================ */
/* .. Parameters .. */
/* ==== Matrices of order NTINY or smaller must be processed by */
/* . SLAHQR because of insufficient subdiagonal scratch space. */
/* . (This is a hard limit.) ==== */
/* ==== NL allocates some local workspace to help small matrices */
/* . through a rare SLAHQR failure. NL .GT. NTINY = 11 is */
/* . required and NL .LE. NMIN = ILAENV(ISPEC=12,...) is recom- */
/* . mended. (The default value of NMIN is 75.) Using NL = 49 */
/* . allows up to six simultaneous shifts and a 16-by-16 */
/* . deflation window. ==== */
/* .. */
/* .. Local Arrays .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* ==== Decode and check the input parameters. ==== */
/* Parameter adjustments */
h_dim1 = *ldh;
h_offset = 1 + h_dim1;
h__ -= h_offset;
--wr;
--wi;
z_dim1 = *ldz;
z_offset = 1 + z_dim1;
z__ -= z_offset;
--work;
/* Function Body */
wantt = lsame_(job, "S");
initz = lsame_(compz, "I");
wantz = initz || lsame_(compz, "V");
work[1] = (real) max(1,*n);
lquery = *lwork == -1;
*info = 0;
if (! lsame_(job, "E") && ! wantt) {
*info = -1;
} else if (! lsame_(compz, "N") && ! wantz) {
*info = -2;
} else if (*n < 0) {
*info = -3;
} else if (*ilo < 1 || *ilo > max(1,*n)) {
*info = -4;
} else if (*ihi < min(*ilo,*n) || *ihi > *n) {
*info = -5;
} else if (*ldh < max(1,*n)) {
*info = -7;
} else if (*ldz < 1 || wantz && *ldz < max(1,*n)) {
*info = -11;
} else if (*lwork < max(1,*n) && ! lquery) {
*info = -13;
}
if (*info != 0) {
/* ==== Quick return in case of invalid argument. ==== */
i__1 = -(*info);
xerbla_("SHSEQR", &i__1);
return 0;
} else if (*n == 0) {
/* ==== Quick return in case N = 0; nothing to do. ==== */
return 0;
} else if (lquery) {
/* ==== Quick return in case of a workspace query ==== */
slaqr0_(&wantt, &wantz, n, ilo, ihi, &h__[h_offset], ldh, &wr[1], &wi[
1], ilo, ihi, &z__[z_offset], ldz, &work[1], lwork, info);
/* ==== Ensure reported workspace size is backward-compatible with */
/* . previous LAPACK versions. ==== */
/* Computing MAX */
r__1 = (real) max(1,*n);
work[1] = dmax(r__1,work[1]);
return 0;
} else {
/* ==== copy eigenvalues isolated by SGEBAL ==== */
i__1 = *ilo - 1;
for (i__ = 1; i__ <= i__1; ++i__) {
wr[i__] = h__[i__ + i__ * h_dim1];
wi[i__] = 0.f;
/* L10: */
}
i__1 = *n;
for (i__ = *ihi + 1; i__ <= i__1; ++i__) {
wr[i__] = h__[i__ + i__ * h_dim1];
wi[i__] = 0.f;
/* L20: */
}
/* ==== Initialize Z, if requested ==== */
if (initz) {
slaset_("A", n, n, &c_b11, &c_b12, &z__[z_offset], ldz)
;
}
/* ==== Quick return if possible ==== */
if (*ilo == *ihi) {
wr[*ilo] = h__[*ilo + *ilo * h_dim1];
wi[*ilo] = 0.f;
return 0;
}
/* ==== SLAHQR/SLAQR0 crossover point ==== */
/* Writing concatenation */
i__2[0] = 1, a__1[0] = job;
i__2[1] = 1, a__1[1] = compz;
s_cat(ch__1, a__1, i__2, &c__2, (ftnlen)2);
nmin = ilaenv_(&c__12, "SHSEQR", ch__1, n, ilo, ihi, lwork);
nmin = max(11,nmin);
/* ==== SLAQR0 for big matrices; SLAHQR for small ones ==== */
if (*n > nmin) {
slaqr0_(&wantt, &wantz, n, ilo, ihi, &h__[h_offset], ldh, &wr[1],
&wi[1], ilo, ihi, &z__[z_offset], ldz, &work[1], lwork,
info);
} else {
/* ==== Small matrix ==== */
slahqr_(&wantt, &wantz, n, ilo, ihi, &h__[h_offset], ldh, &wr[1],
&wi[1], ilo, ihi, &z__[z_offset], ldz, info);
if (*info > 0) {
/* ==== A rare SLAHQR failure! SLAQR0 sometimes succeeds */
/* . when SLAHQR fails. ==== */
kbot = *info;
if (*n >= 49) {
/* ==== Larger matrices have enough subdiagonal scratch */
/* . space to call SLAQR0 directly. ==== */
slaqr0_(&wantt, &wantz, n, ilo, &kbot, &h__[h_offset],
ldh, &wr[1], &wi[1], ilo, ihi, &z__[z_offset],
ldz, &work[1], lwork, info);
} else {
/* ==== Tiny matrices don't have enough subdiagonal */
/* . scratch space to benefit from SLAQR0. Hence, */
/* . tiny matrices must be copied into a larger */
/* . array before calling SLAQR0. ==== */
slacpy_("A", n, n, &h__[h_offset], ldh, hl, &c__49);
hl[*n + 1 + *n * 49 - 50] = 0.f;
i__1 = 49 - *n;
slaset_("A", &c__49, &i__1, &c_b11, &c_b11, &hl[(*n + 1) *
49 - 49], &c__49);
slaqr0_(&wantt, &wantz, &c__49, ilo, &kbot, hl, &c__49, &
wr[1], &wi[1], ilo, ihi, &z__[z_offset], ldz,
workl, &c__49, info);
if (wantt || *info != 0) {
slacpy_("A", n, n, hl, &c__49, &h__[h_offset], ldh);
}
}
}
}
/* ==== Clear out the trash, if necessary. ==== */
if ((wantt || *info != 0) && *n > 2) {
i__1 = *n - 2;
i__3 = *n - 2;
slaset_("L", &i__1, &i__3, &c_b11, &c_b11, &h__[h_dim1 + 3], ldh);
}
/* ==== Ensure reported workspace size is backward-compatible with */
/* . previous LAPACK versions. ==== */
/* Computing MAX */
r__1 = (real) max(1,*n);
work[1] = dmax(r__1,work[1]);
}
/* ==== End of SHSEQR ==== */
return 0;
} /* shseqr_ */
