int
f2c_ztbsv(char* uplo, char* trans, char* diag, integer* N, integer* K,
doublecomplex* A, integer* lda,
doublecomplex* X, integer* incX)
{
ztbsv_(uplo, trans, diag,
N, K, A, lda, X, incX);
return 0;
}
void
ztbsv(char uplo, char trans, char diag, int n, int k, doublecomplex *a, int lda, doublecomplex *x, int incx )
{
ztbsv_( &uplo, &trans, &diag, &n, &k, a, &lda, x, &incx );
}
/* Subroutine */
int ztbrfs_(char *uplo, char *trans, char *diag, integer *n, integer *kd, integer *nrhs, doublecomplex *ab, integer *ldab, doublecomplex *b, integer *ldb, doublecomplex *x, integer *ldx, doublereal *ferr, doublereal *berr, doublecomplex *work, doublereal * rwork, integer *info)
{
/* System generated locals */
integer ab_dim1, ab_offset, b_dim1, b_offset, x_dim1, x_offset, i__1, i__2, i__3, i__4, i__5;
doublereal d__1, d__2, d__3, d__4;
doublecomplex z__1;
/* Builtin functions */
double d_imag(doublecomplex *);
/* Local variables */
integer i__, j, k;
doublereal s, xk;
integer nz;
doublereal eps;
integer kase;
doublereal safe1, safe2;
extern logical lsame_(char *, char *);
integer isave[3];
logical upper;
extern /* Subroutine */
int ztbmv_(char *, char *, char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *), zcopy_(integer *, doublecomplex *, integer *, doublecomplex *, integer *), ztbsv_(char *, char *, char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *), zaxpy_( integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), zlacn2_(integer *, doublecomplex *, doublecomplex *, doublereal *, integer *, integer *);
extern doublereal dlamch_(char *);
doublereal safmin;
extern /* Subroutine */
int xerbla_(char *, integer *);
logical notran;
char transn[1], transt[1];
logical nounit;
doublereal lstres;
/* -- LAPACK computational routine (version 3.4.0) -- */
/* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
/* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
/* November 2011 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. Local Arrays .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. Statement Functions .. */
/* .. */
/* .. Statement Function definitions .. */
/* .. */
/* .. Executable Statements .. */
/* Test the input parameters. */
/* Parameter adjustments */
ab_dim1 = *ldab;
ab_offset = 1 + ab_dim1;
ab -= ab_offset;
b_dim1 = *ldb;
b_offset = 1 + b_dim1;
b -= b_offset;
x_dim1 = *ldx;
x_offset = 1 + x_dim1;
x -= x_offset;
--ferr;
--berr;
--work;
--rwork;
/* Function Body */
*info = 0;
upper = lsame_(uplo, "U");
notran = lsame_(trans, "N");
nounit = lsame_(diag, "N");
if (! upper && ! lsame_(uplo, "L"))
{
*info = -1;
}
else if (! notran && ! lsame_(trans, "T") && ! lsame_(trans, "C"))
{
*info = -2;
}
else if (! nounit && ! lsame_(diag, "U"))
{
*info = -3;
}
else if (*n < 0)
{
*info = -4;
}
else if (*kd < 0)
{
*info = -5;
}
else if (*nrhs < 0)
{
*info = -6;
}
else if (*ldab < *kd + 1)
{
*info = -8;
}
else if (*ldb < max(1,*n))
{
*info = -10;
}
else if (*ldx < max(1,*n))
{
*info = -12;
}
if (*info != 0)
{
i__1 = -(*info);
xerbla_("ZTBRFS", &i__1);
return 0;
}
/* Quick return if possible */
if (*n == 0 || *nrhs == 0)
{
i__1 = *nrhs;
for (j = 1;
j <= i__1;
++j)
{
ferr[j] = 0.;
berr[j] = 0.;
/* L10: */
}
return 0;
}
if (notran)
{
*(unsigned char *)transn = 'N';
*(unsigned char *)transt = 'C';
}
else
{
*(unsigned char *)transn = 'C';
*(unsigned char *)transt = 'N';
}
/* NZ = maximum number of nonzero elements in each row of A, plus 1 */
nz = *kd + 2;
eps = dlamch_("Epsilon");
safmin = dlamch_("Safe minimum");
safe1 = nz * safmin;
safe2 = safe1 / eps;
/* Do for each right hand side */
i__1 = *nrhs;
for (j = 1;
j <= i__1;
++j)
{
/* Compute residual R = B - op(A) * X, */
/* where op(A) = A, A**T, or A**H, depending on TRANS. */
zcopy_(n, &x[j * x_dim1 + 1], &c__1, &work[1], &c__1);
ztbmv_(uplo, trans, diag, n, kd, &ab[ab_offset], ldab, &work[1], & c__1);
z__1.r = -1.;
z__1.i = -0.; // , expr subst
zaxpy_(n, &z__1, &b[j * b_dim1 + 1], &c__1, &work[1], &c__1);
/* Compute componentwise relative backward error from formula */
/* max(i) ( abs(R(i)) / ( abs(op(A))*abs(X) + abs(B) )(i) ) */
/* where abs(Z) is the componentwise absolute value of the matrix */
/* or vector Z. If the i-th component of the denominator is less */
/* than SAFE2, then SAFE1 is added to the i-th components of the */
/* numerator and denominator before dividing. */
i__2 = *n;
for (i__ = 1;
i__ <= i__2;
++i__)
{
i__3 = i__ + j * b_dim1;
rwork[i__] = (d__1 = b[i__3].r, abs(d__1)) + (d__2 = d_imag(&b[ i__ + j * b_dim1]), abs(d__2));
/* L20: */
}
if (notran)
{
/* Compute abs(A)*abs(X) + abs(B). */
if (upper)
{
if (nounit)
{
i__2 = *n;
for (k = 1;
k <= i__2;
++k)
{
i__3 = k + j * x_dim1;
xk = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(& x[k + j * x_dim1]), abs(d__2));
/* Computing MAX */
i__3 = 1;
i__4 = k - *kd; // , expr subst
i__5 = k;
for (i__ = max(i__3,i__4);
i__ <= i__5;
++i__)
{
i__3 = *kd + 1 + i__ - k + k * ab_dim1;
rwork[i__] += ((d__1 = ab[i__3].r, abs(d__1)) + ( d__2 = d_imag(&ab[*kd + 1 + i__ - k + k * ab_dim1]), abs(d__2))) * xk;
/* L30: */
}
/* L40: */
}
}
else
{
i__2 = *n;
for (k = 1;
k <= i__2;
++k)
{
i__5 = k + j * x_dim1;
xk = (d__1 = x[i__5].r, abs(d__1)) + (d__2 = d_imag(& x[k + j * x_dim1]), abs(d__2));
/* Computing MAX */
i__5 = 1;
i__3 = k - *kd; // , expr subst
i__4 = k - 1;
for (i__ = max(i__5,i__3);
i__ <= i__4;
++i__)
{
i__5 = *kd + 1 + i__ - k + k * ab_dim1;
rwork[i__] += ((d__1 = ab[i__5].r, abs(d__1)) + ( d__2 = d_imag(&ab[*kd + 1 + i__ - k + k * ab_dim1]), abs(d__2))) * xk;
/* L50: */
}
rwork[k] += xk;
/* L60: */
}
}
}
else
{
if (nounit)
{
i__2 = *n;
for (k = 1;
k <= i__2;
++k)
{
i__4 = k + j * x_dim1;
xk = (d__1 = x[i__4].r, abs(d__1)) + (d__2 = d_imag(& x[k + j * x_dim1]), abs(d__2));
/* Computing MIN */
i__5 = *n;
i__3 = k + *kd; // , expr subst
i__4 = min(i__5,i__3);
for (i__ = k;
i__ <= i__4;
++i__)
{
i__5 = i__ + 1 - k + k * ab_dim1;
rwork[i__] += ((d__1 = ab[i__5].r, abs(d__1)) + ( d__2 = d_imag(&ab[i__ + 1 - k + k * ab_dim1]), abs(d__2))) * xk;
/* L70: */
}
/* L80: */
}
}
else
{
i__2 = *n;
for (k = 1;
k <= i__2;
++k)
{
i__4 = k + j * x_dim1;
xk = (d__1 = x[i__4].r, abs(d__1)) + (d__2 = d_imag(& x[k + j * x_dim1]), abs(d__2));
/* Computing MIN */
i__5 = *n;
i__3 = k + *kd; // , expr subst
i__4 = min(i__5,i__3);
for (i__ = k + 1;
i__ <= i__4;
++i__)
{
i__5 = i__ + 1 - k + k * ab_dim1;
rwork[i__] += ((d__1 = ab[i__5].r, abs(d__1)) + ( d__2 = d_imag(&ab[i__ + 1 - k + k * ab_dim1]), abs(d__2))) * xk;
/* L90: */
}
rwork[k] += xk;
/* L100: */
}
}
}
}
else
{
/* Compute abs(A**H)*abs(X) + abs(B). */
if (upper)
{
if (nounit)
{
i__2 = *n;
for (k = 1;
k <= i__2;
++k)
{
s = 0.;
/* Computing MAX */
i__4 = 1;
i__5 = k - *kd; // , expr subst
i__3 = k;
for (i__ = max(i__4,i__5);
i__ <= i__3;
++i__)
{
i__4 = *kd + 1 + i__ - k + k * ab_dim1;
i__5 = i__ + j * x_dim1;
s += ((d__1 = ab[i__4].r, abs(d__1)) + (d__2 = d_imag(&ab[*kd + 1 + i__ - k + k * ab_dim1]), abs(d__2))) * ((d__3 = x[i__5] .r, abs(d__3)) + (d__4 = d_imag(&x[i__ + j * x_dim1]), abs(d__4)));
/* L110: */
}
rwork[k] += s;
/* L120: */
}
}
else
{
i__2 = *n;
for (k = 1;
k <= i__2;
++k)
{
i__3 = k + j * x_dim1;
s = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[ k + j * x_dim1]), abs(d__2));
/* Computing MAX */
i__3 = 1;
i__4 = k - *kd; // , expr subst
i__5 = k - 1;
for (i__ = max(i__3,i__4);
i__ <= i__5;
++i__)
{
i__3 = *kd + 1 + i__ - k + k * ab_dim1;
i__4 = i__ + j * x_dim1;
s += ((d__1 = ab[i__3].r, abs(d__1)) + (d__2 = d_imag(&ab[*kd + 1 + i__ - k + k * ab_dim1]), abs(d__2))) * ((d__3 = x[i__4] .r, abs(d__3)) + (d__4 = d_imag(&x[i__ + j * x_dim1]), abs(d__4)));
/* L130: */
}
rwork[k] += s;
/* L140: */
}
}
}
else
{
if (nounit)
{
i__2 = *n;
for (k = 1;
k <= i__2;
++k)
{
s = 0.;
/* Computing MIN */
i__3 = *n;
i__4 = k + *kd; // , expr subst
i__5 = min(i__3,i__4);
for (i__ = k;
i__ <= i__5;
++i__)
{
i__3 = i__ + 1 - k + k * ab_dim1;
i__4 = i__ + j * x_dim1;
s += ((d__1 = ab[i__3].r, abs(d__1)) + (d__2 = d_imag(&ab[i__ + 1 - k + k * ab_dim1]), abs(d__2))) * ((d__3 = x[i__4].r, abs( d__3)) + (d__4 = d_imag(&x[i__ + j * x_dim1]), abs(d__4)));
/* L150: */
}
rwork[k] += s;
/* L160: */
}
}
else
{
i__2 = *n;
for (k = 1;
k <= i__2;
++k)
{
i__5 = k + j * x_dim1;
s = (d__1 = x[i__5].r, abs(d__1)) + (d__2 = d_imag(&x[ k + j * x_dim1]), abs(d__2));
/* Computing MIN */
i__3 = *n;
i__4 = k + *kd; // , expr subst
i__5 = min(i__3,i__4);
for (i__ = k + 1;
i__ <= i__5;
++i__)
{
i__3 = i__ + 1 - k + k * ab_dim1;
i__4 = i__ + j * x_dim1;
s += ((d__1 = ab[i__3].r, abs(d__1)) + (d__2 = d_imag(&ab[i__ + 1 - k + k * ab_dim1]), abs(d__2))) * ((d__3 = x[i__4].r, abs( d__3)) + (d__4 = d_imag(&x[i__ + j * x_dim1]), abs(d__4)));
/* L170: */
}
rwork[k] += s;
/* L180: */
}
}
}
}
s = 0.;
i__2 = *n;
for (i__ = 1;
i__ <= i__2;
++i__)
{
if (rwork[i__] > safe2)
{
/* Computing MAX */
i__5 = i__;
d__3 = s;
d__4 = ((d__1 = work[i__5].r, abs(d__1)) + (d__2 = d_imag(&work[i__]), abs(d__2))) / rwork[i__]; // , expr subst
s = max(d__3,d__4);
}
else
{
/* Computing MAX */
i__5 = i__;
d__3 = s;
d__4 = ((d__1 = work[i__5].r, abs(d__1)) + (d__2 = d_imag(&work[i__]), abs(d__2)) + safe1) / (rwork[i__] + safe1); // , expr subst
s = max(d__3,d__4);
}
/* L190: */
}
berr[j] = s;
/* Bound error from formula */
/* norm(X - XTRUE) / norm(X) .le. FERR = */
/* norm( abs(inv(op(A)))* */
/* ( abs(R) + NZ*EPS*( abs(op(A))*abs(X)+abs(B) ))) / norm(X) */
/* where */
/* norm(Z) is the magnitude of the largest component of Z */
/* inv(op(A)) is the inverse of op(A) */
/* abs(Z) is the componentwise absolute value of the matrix or */
/* vector Z */
/* NZ is the maximum number of nonzeros in any row of A, plus 1 */
/* EPS is machine epsilon */
/* The i-th component of abs(R)+NZ*EPS*(abs(op(A))*abs(X)+abs(B)) */
/* is incremented by SAFE1 if the i-th component of */
/* abs(op(A))*abs(X) + abs(B) is less than SAFE2. */
/* Use ZLACN2 to estimate the infinity-norm of the matrix */
/* inv(op(A)) * diag(W), */
/* where W = abs(R) + NZ*EPS*( abs(op(A))*abs(X)+abs(B) ))) */
i__2 = *n;
for (i__ = 1;
i__ <= i__2;
++i__)
{
if (rwork[i__] > safe2)
{
i__5 = i__;
rwork[i__] = (d__1 = work[i__5].r, abs(d__1)) + (d__2 = d_imag(&work[i__]), abs(d__2)) + nz * eps * rwork[i__] ;
}
else
{
i__5 = i__;
rwork[i__] = (d__1 = work[i__5].r, abs(d__1)) + (d__2 = d_imag(&work[i__]), abs(d__2)) + nz * eps * rwork[i__] + safe1;
}
/* L200: */
}
kase = 0;
L210:
zlacn2_(n, &work[*n + 1], &work[1], &ferr[j], &kase, isave);
if (kase != 0)
{
if (kase == 1)
{
/* Multiply by diag(W)*inv(op(A)**H). */
ztbsv_(uplo, transt, diag, n, kd, &ab[ab_offset], ldab, &work[ 1], &c__1);
i__2 = *n;
for (i__ = 1;
i__ <= i__2;
++i__)
{
i__5 = i__;
i__3 = i__;
i__4 = i__;
z__1.r = rwork[i__3] * work[i__4].r;
z__1.i = rwork[i__3] * work[i__4].i; // , expr subst
work[i__5].r = z__1.r;
work[i__5].i = z__1.i; // , expr subst
/* L220: */
}
}
else
{
/* Multiply by inv(op(A))*diag(W). */
i__2 = *n;
for (i__ = 1;
i__ <= i__2;
++i__)
{
i__5 = i__;
i__3 = i__;
i__4 = i__;
z__1.r = rwork[i__3] * work[i__4].r;
z__1.i = rwork[i__3] * work[i__4].i; // , expr subst
work[i__5].r = z__1.r;
work[i__5].i = z__1.i; // , expr subst
/* L230: */
}
ztbsv_(uplo, transn, diag, n, kd, &ab[ab_offset], ldab, &work[ 1], &c__1);
}
goto L210;
}
/* Normalize error. */
lstres = 0.;
i__2 = *n;
for (i__ = 1;
i__ <= i__2;
++i__)
{
/* Computing MAX */
i__5 = i__ + j * x_dim1;
d__3 = lstres;
d__4 = (d__1 = x[i__5].r, abs(d__1)) + (d__2 = d_imag(&x[i__ + j * x_dim1]), abs(d__2)); // , expr subst
lstres = max(d__3,d__4);
/* L240: */
}
if (lstres != 0.)
{
ferr[j] /= lstres;
}
/* L250: */
}
return 0;
/* End of ZTBRFS */
}
/* Subroutine */ int zpbtrs_(char *uplo, integer *n, integer *kd, integer *
nrhs, doublecomplex *ab, integer *ldab, doublecomplex *b, integer *
ldb, integer *info)
{
/* System generated locals */
integer ab_dim1, ab_offset, b_dim1, b_offset, i__1;
/* Local variables */
integer j;
extern logical lsame_(char *, char *);
logical upper;
extern /* Subroutine */ int ztbsv_(char *, char *, char *, integer *,
integer *, doublecomplex *, integer *, doublecomplex *, integer *), xerbla_(char *, integer *);
/* -- LAPACK routine (version 3.1) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* ZPBTRS solves a system of linear equations A*X = B with a Hermitian */
/* positive definite band matrix A using the Cholesky factorization */
/* A = U**H*U or A = L*L**H computed by ZPBTRF. */
/* Arguments */
/* ========= */
/* UPLO (input) CHARACTER*1 */
/* = 'U': Upper triangular factor stored in AB; */
/* = 'L': Lower triangular factor stored in AB. */
/* N (input) INTEGER */
/* The order of the matrix A. N >= 0. */
/* KD (input) INTEGER */
/* The number of superdiagonals of the matrix A if UPLO = 'U', */
/* or the number of subdiagonals if UPLO = 'L'. KD >= 0. */
/* NRHS (input) INTEGER */
/* The number of right hand sides, i.e., the number of columns */
/* of the matrix B. NRHS >= 0. */
/* AB (input) COMPLEX*16 array, dimension (LDAB,N) */
/* The triangular factor U or L from the Cholesky factorization */
/* A = U**H*U or A = L*L**H of the band matrix A, stored in the */
/* first KD+1 rows of the array. The j-th column of U or L is */
/* stored in the j-th column of the array AB as follows: */
/* if UPLO ='U', AB(kd+1+i-j,j) = U(i,j) for max(1,j-kd)<=i<=j; */
/* if UPLO ='L', AB(1+i-j,j) = L(i,j) for j<=i<=min(n,j+kd). */
/* LDAB (input) INTEGER */
/* The leading dimension of the array AB. LDAB >= KD+1. */
/* B (input/output) COMPLEX*16 array, dimension (LDB,NRHS) */
/* On entry, the right hand side matrix B. */
/* On exit, the solution matrix X. */
/* LDB (input) INTEGER */
/* The leading dimension of the array B. LDB >= max(1,N). */
/* INFO (output) INTEGER */
/* = 0: successful exit */
/* < 0: if INFO = -i, the i-th argument had an illegal value */
/* ===================================================================== */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Test the input parameters. */
/* Parameter adjustments */
ab_dim1 = *ldab;
ab_offset = 1 + ab_dim1;
ab -= ab_offset;
b_dim1 = *ldb;
b_offset = 1 + b_dim1;
b -= b_offset;
/* Function Body */
*info = 0;
upper = lsame_(uplo, "U");
if (! upper && ! lsame_(uplo, "L")) {
*info = -1;
} else if (*n < 0) {
*info = -2;
} else if (*kd < 0) {
*info = -3;
} else if (*nrhs < 0) {
*info = -4;
} else if (*ldab < *kd + 1) {
*info = -6;
} else if (*ldb < max(1,*n)) {
*info = -8;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("ZPBTRS", &i__1);
return 0;
}
/* Quick return if possible */
if (*n == 0 || *nrhs == 0) {
return 0;
}
if (upper) {
/* Solve A*X = B where A = U'*U. */
i__1 = *nrhs;
for (j = 1; j <= i__1; ++j) {
/* Solve U'*X = B, overwriting B with X. */
ztbsv_("Upper", "Conjugate transpose", "Non-unit", n, kd, &ab[
ab_offset], ldab, &b[j * b_dim1 + 1], &c__1);
/* Solve U*X = B, overwriting B with X. */
ztbsv_("Upper", "No transpose", "Non-unit", n, kd, &ab[ab_offset],
ldab, &b[j * b_dim1 + 1], &c__1);
/* L10: */
}
} else {
/* Solve A*X = B where A = L*L'. */
i__1 = *nrhs;
for (j = 1; j <= i__1; ++j) {
/* Solve L*X = B, overwriting B with X. */
ztbsv_("Lower", "No transpose", "Non-unit", n, kd, &ab[ab_offset],
ldab, &b[j * b_dim1 + 1], &c__1);
/* Solve L'*X = B, overwriting B with X. */
ztbsv_("Lower", "Conjugate transpose", "Non-unit", n, kd, &ab[
ab_offset], ldab, &b[j * b_dim1 + 1], &c__1);
/* L20: */
}
}
return 0;
/* End of ZPBTRS */
} /* zpbtrs_ */
/* Subroutine */ int ztbrfs_(char *uplo, char *trans, char *diag, integer *n,
integer *kd, integer *nrhs, doublecomplex *ab, integer *ldab,
doublecomplex *b, integer *ldb, doublecomplex *x, integer *ldx,
doublereal *ferr, doublereal *berr, doublecomplex *work, doublereal *
rwork, integer *info)
{
/* -- LAPACK routine (version 2.0) --
Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
Courant Institute, Argonne National Lab, and Rice University
September 30, 1994
Purpose
=======
ZTBRFS provides error bounds and backward error estimates for the
solution to a system of linear equations with a triangular band
coefficient matrix.
The solution matrix X must be computed by ZTBTRS or some other
means before entering this routine. ZTBRFS does not do iterative
refinement because doing so cannot improve the backward error.
Arguments
=========
UPLO (input) CHARACTER*1
= 'U': A is upper triangular;
= 'L': A is lower triangular.
TRANS (input) CHARACTER*1
Specifies the form of the system of equations:
= 'N': A * X = B (No transpose)
= 'T': A**T * X = B (Transpose)
= 'C': A**H * X = B (Conjugate transpose)
DIAG (input) CHARACTER*1
= 'N': A is non-unit triangular;
= 'U': A is unit triangular.
N (input) INTEGER
The order of the matrix A. N >= 0.
KD (input) INTEGER
The number of superdiagonals or subdiagonals of the
triangular band matrix A. KD >= 0.
NRHS (input) INTEGER
The number of right hand sides, i.e., the number of columns
of the matrices B and X. NRHS >= 0.
AB (input) COMPLEX*16 array, dimension (LDAB,N)
The upper or lower triangular band matrix A, stored in the
first kd+1 rows of the array. The j-th column of A is stored
in the j-th column of the array AB as follows:
if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j;
if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j<=i<=min(n,j+kd).
If DIAG = 'U', the diagonal elements of A are not referenced
and are assumed to be 1.
LDAB (input) INTEGER
The leading dimension of the array AB. LDAB >= KD+1.
B (input) COMPLEX*16 array, dimension (LDB,NRHS)
The right hand side matrix B.
LDB (input) INTEGER
The leading dimension of the array B. LDB >= max(1,N).
X (input) COMPLEX*16 array, dimension (LDX,NRHS)
The solution matrix X.
LDX (input) INTEGER
The leading dimension of the array X. LDX >= max(1,N).
FERR (output) DOUBLE PRECISION array, dimension (NRHS)
The estimated forward error bound for each solution vector
X(j) (the j-th column of the solution matrix X).
If XTRUE is the true solution corresponding to X(j), FERR(j)
is an estimated upper bound for the magnitude of the largest
element in (X(j) - XTRUE) divided by the magnitude of the
largest element in X(j). The estimate is as reliable as
the estimate for RCOND, and is almost always a slight
overestimate of the true error.
BERR (output) DOUBLE PRECISION array, dimension (NRHS)
The componentwise relative backward error of each solution
vector X(j) (i.e., the smallest relative change in
any element of A or B that makes X(j) an exact solution).
WORK (workspace) COMPLEX*16 array, dimension (2*N)
RWORK (workspace) DOUBLE PRECISION array, dimension (N)
INFO (output) INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
=====================================================================
Test the input parameters.
Parameter adjustments
Function Body */
/* Table of constant values */
static integer c__1 = 1;
/* System generated locals */
integer ab_dim1, ab_offset, b_dim1, b_offset, x_dim1, x_offset, i__1,
i__2, i__3, i__4, i__5;
doublereal d__1, d__2, d__3, d__4;
doublecomplex z__1;
/* Builtin functions */
double d_imag(doublecomplex *);
/* Local variables */
static integer kase;
static doublereal safe1, safe2;
static integer i, j, k;
static doublereal s;
extern logical lsame_(char *, char *);
static logical upper;
extern /* Subroutine */ int ztbmv_(char *, char *, char *, integer *,
integer *, doublecomplex *, integer *, doublecomplex *, integer *), zcopy_(integer *, doublecomplex *,
integer *, doublecomplex *, integer *), ztbsv_(char *, char *,
char *, integer *, integer *, doublecomplex *, integer *,
doublecomplex *, integer *), zaxpy_(
integer *, doublecomplex *, doublecomplex *, integer *,
doublecomplex *, integer *);
extern doublereal dlamch_(char *);
static doublereal xk;
static integer nz;
static doublereal safmin;
extern /* Subroutine */ int xerbla_(char *, integer *), zlacon_(
integer *, doublecomplex *, doublecomplex *, doublereal *,
integer *);
static logical notran;
static char transn[1], transt[1];
static logical nounit;
static doublereal lstres, eps;
#define FERR(I) ferr[(I)-1]
#define BERR(I) berr[(I)-1]
#define WORK(I) work[(I)-1]
#define RWORK(I) rwork[(I)-1]
#define AB(I,J) ab[(I)-1 + ((J)-1)* ( *ldab)]
#define B(I,J) b[(I)-1 + ((J)-1)* ( *ldb)]
#define X(I,J) x[(I)-1 + ((J)-1)* ( *ldx)]
*info = 0;
upper = lsame_(uplo, "U");
notran = lsame_(trans, "N");
nounit = lsame_(diag, "N");
if (! upper && ! lsame_(uplo, "L")) {
*info = -1;
} else if (! notran && ! lsame_(trans, "T") && ! lsame_(trans,
"C")) {
*info = -2;
} else if (! nounit && ! lsame_(diag, "U")) {
*info = -3;
} else if (*n < 0) {
*info = -4;
} else if (*kd < 0) {
*info = -5;
} else if (*nrhs < 0) {
*info = -6;
} else if (*ldab < *kd + 1) {
*info = -8;
} else if (*ldb < max(1,*n)) {
*info = -10;
} else if (*ldx < max(1,*n)) {
*info = -12;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("ZTBRFS", &i__1);
return 0;
}
/* Quick return if possible */
if (*n == 0 || *nrhs == 0) {
i__1 = *nrhs;
for (j = 1; j <= *nrhs; ++j) {
FERR(j) = 0.;
BERR(j) = 0.;
/* L10: */
}
return 0;
}
if (notran) {
*(unsigned char *)transn = 'N';
*(unsigned char *)transt = 'C';
} else {
*(unsigned char *)transn = 'C';
*(unsigned char *)transt = 'N';
}
/* NZ = maximum number of nonzero elements in each row of A, plus 1 */
nz = *kd + 2;
eps = dlamch_("Epsilon");
safmin = dlamch_("Safe minimum");
safe1 = nz * safmin;
safe2 = safe1 / eps;
/* Do for each right hand side */
i__1 = *nrhs;
for (j = 1; j <= *nrhs; ++j) {
/* Compute residual R = B - op(A) * X,
where op(A) = A, A**T, or A**H, depending on TRANS. */
zcopy_(n, &X(1,j), &c__1, &WORK(1), &c__1);
ztbmv_(uplo, trans, diag, n, kd, &AB(1,1), ldab, &WORK(1), &
c__1);
z__1.r = -1., z__1.i = 0.;
zaxpy_(n, &z__1, &B(1,j), &c__1, &WORK(1), &c__1);
/* Compute componentwise relative backward error from formula
max(i) ( abs(R(i)) / ( abs(op(A))*abs(X) + abs(B) )(i) )
where abs(Z) is the componentwise absolute value of the matr
ix
or vector Z. If the i-th component of the denominator is le
ss
than SAFE2, then SAFE1 is added to the i-th components of th
e
numerator and denominator before dividing. */
i__2 = *n;
for (i = 1; i <= *n; ++i) {
i__3 = i + j * b_dim1;
RWORK(i) = (d__1 = B(i,j).r, abs(d__1)) + (d__2 = d_imag(&B(i,j)), abs(d__2));
/* L20: */
}
if (notran) {
/* Compute abs(A)*abs(X) + abs(B). */
if (upper) {
if (nounit) {
i__2 = *n;
for (k = 1; k <= *n; ++k) {
i__3 = k + j * x_dim1;
xk = (d__1 = X(k,j).r, abs(d__1)) + (d__2 = d_imag(&
X(k,j)), abs(d__2));
/* Computing MAX */
i__3 = 1, i__4 = k - *kd;
i__5 = k;
for (i = max(1,k-*kd); i <= k; ++i) {
i__3 = *kd + 1 + i - k + k * ab_dim1;
RWORK(i) += ((d__1 = AB(*kd+1+i-k,k).r, abs(d__1)) + (
d__2 = d_imag(&AB(*kd+1+i-k,k)), abs(d__2))) * xk;
/* L30: */
}
/* L40: */
}
} else {
i__2 = *n;
for (k = 1; k <= *n; ++k) {
i__5 = k + j * x_dim1;
xk = (d__1 = X(k,j).r, abs(d__1)) + (d__2 = d_imag(&
X(k,j)), abs(d__2));
/* Computing MAX */
i__5 = 1, i__3 = k - *kd;
i__4 = k - 1;
for (i = max(1,k-*kd); i <= k-1; ++i) {
i__5 = *kd + 1 + i - k + k * ab_dim1;
RWORK(i) += ((d__1 = AB(*kd+1+i-k,k).r, abs(d__1)) + (
d__2 = d_imag(&AB(*kd+1+i-k,k)), abs(d__2))) * xk;
/* L50: */
}
RWORK(k) += xk;
/* L60: */
}
}
} else {
if (nounit) {
i__2 = *n;
for (k = 1; k <= *n; ++k) {
i__4 = k + j * x_dim1;
xk = (d__1 = X(k,j).r, abs(d__1)) + (d__2 = d_imag(&
X(k,j)), abs(d__2));
/* Computing MIN */
i__5 = *n, i__3 = k + *kd;
i__4 = min(i__5,i__3);
for (i = k; i <= min(*n,k+*kd); ++i) {
i__5 = i + 1 - k + k * ab_dim1;
RWORK(i) += ((d__1 = AB(i+1-k,k).r, abs(d__1)) + (
d__2 = d_imag(&AB(i+1-k,k)
), abs(d__2))) * xk;
/* L70: */
}
/* L80: */
}
} else {
i__2 = *n;
for (k = 1; k <= *n; ++k) {
i__4 = k + j * x_dim1;
xk = (d__1 = X(k,j).r, abs(d__1)) + (d__2 = d_imag(&
X(k,j)), abs(d__2));
/* Computing MIN */
i__5 = *n, i__3 = k + *kd;
i__4 = min(i__5,i__3);
for (i = k + 1; i <= min(*n,k+*kd); ++i) {
i__5 = i + 1 - k + k * ab_dim1;
RWORK(i) += ((d__1 = AB(i+1-k,k).r, abs(d__1)) + (
d__2 = d_imag(&AB(i+1-k,k)
), abs(d__2))) * xk;
/* L90: */
}
RWORK(k) += xk;
/* L100: */
}
}
}
} else {
/* Compute abs(A**H)*abs(X) + abs(B). */
if (upper) {
if (nounit) {
i__2 = *n;
for (k = 1; k <= *n; ++k) {
s = 0.;
/* Computing MAX */
i__4 = 1, i__5 = k - *kd;
i__3 = k;
for (i = max(1,k-*kd); i <= k; ++i) {
i__4 = *kd + 1 + i - k + k * ab_dim1;
i__5 = i + j * x_dim1;
s += ((d__1 = AB(*kd+1+i-k,k).r, abs(d__1)) + (d__2 =
d_imag(&AB(*kd+1+i-k,k))
, abs(d__2))) * ((d__3 = X(i,j).r, abs(
d__3)) + (d__4 = d_imag(&X(i,j)
), abs(d__4)));
/* L110: */
}
RWORK(k) += s;
/* L120: */
}
} else {
i__2 = *n;
for (k = 1; k <= *n; ++k) {
i__3 = k + j * x_dim1;
s = (d__1 = X(k,j).r, abs(d__1)) + (d__2 = d_imag(&X(k,j)), abs(d__2));
/* Computing MAX */
i__3 = 1, i__4 = k - *kd;
i__5 = k - 1;
for (i = max(1,k-*kd); i <= k-1; ++i) {
i__3 = *kd + 1 + i - k + k * ab_dim1;
i__4 = i + j * x_dim1;
s += ((d__1 = AB(*kd+1+i-k,k).r, abs(d__1)) + (d__2 =
d_imag(&AB(*kd+1+i-k,k))
, abs(d__2))) * ((d__3 = X(i,j).r, abs(
d__3)) + (d__4 = d_imag(&X(i,j)
), abs(d__4)));
/* L130: */
}
RWORK(k) += s;
/* L140: */
}
}
} else {
if (nounit) {
i__2 = *n;
for (k = 1; k <= *n; ++k) {
s = 0.;
/* Computing MIN */
i__3 = *n, i__4 = k + *kd;
i__5 = min(i__3,i__4);
for (i = k; i <= min(*n,k+*kd); ++i) {
i__3 = i + 1 - k + k * ab_dim1;
i__4 = i + j * x_dim1;
s += ((d__1 = AB(i+1-k,k).r, abs(d__1)) + (d__2 =
d_imag(&AB(i+1-k,k)), abs(
d__2))) * ((d__3 = X(i,j).r, abs(d__3))
+ (d__4 = d_imag(&X(i,j)), abs(
d__4)));
/* L150: */
}
RWORK(k) += s;
/* L160: */
}
} else {
i__2 = *n;
for (k = 1; k <= *n; ++k) {
i__5 = k + j * x_dim1;
s = (d__1 = X(k,j).r, abs(d__1)) + (d__2 = d_imag(&X(k,j)), abs(d__2));
/* Computing MIN */
i__3 = *n, i__4 = k + *kd;
i__5 = min(i__3,i__4);
for (i = k + 1; i <= min(*n,k+*kd); ++i) {
i__3 = i + 1 - k + k * ab_dim1;
i__4 = i + j * x_dim1;
s += ((d__1 = AB(i+1-k,k).r, abs(d__1)) + (d__2 =
d_imag(&AB(i+1-k,k)), abs(
d__2))) * ((d__3 = X(i,j).r, abs(d__3))
+ (d__4 = d_imag(&X(i,j)), abs(
d__4)));
/* L170: */
}
RWORK(k) += s;
/* L180: */
}
}
}
}
s = 0.;
i__2 = *n;
for (i = 1; i <= *n; ++i) {
if (RWORK(i) > safe2) {
/* Computing MAX */
i__5 = i;
d__3 = s, d__4 = ((d__1 = WORK(i).r, abs(d__1)) + (d__2 =
d_imag(&WORK(i)), abs(d__2))) / RWORK(i);
s = max(d__3,d__4);
} else {
/* Computing MAX */
i__5 = i;
d__3 = s, d__4 = ((d__1 = WORK(i).r, abs(d__1)) + (d__2 =
d_imag(&WORK(i)), abs(d__2)) + safe1) / (RWORK(i) +
safe1);
s = max(d__3,d__4);
}
/* L190: */
}
BERR(j) = s;
/* Bound error from formula
norm(X - XTRUE) / norm(X) .le. FERR =
norm( abs(inv(op(A)))*
( abs(R) + NZ*EPS*( abs(op(A))*abs(X)+abs(B) ))) / norm(X
)
where
norm(Z) is the magnitude of the largest component of Z
inv(op(A)) is the inverse of op(A)
abs(Z) is the componentwise absolute value of the matrix o
r
vector Z
NZ is the maximum number of nonzeros in any row of A, plus
1
EPS is machine epsilon
The i-th component of abs(R)+NZ*EPS*(abs(op(A))*abs(X)+abs(B
))
is incremented by SAFE1 if the i-th component of
abs(op(A))*abs(X) + abs(B) is less than SAFE2.
Use ZLACON to estimate the infinity-norm of the matrix
inv(op(A)) * diag(W),
where W = abs(R) + NZ*EPS*( abs(op(A))*abs(X)+abs(B) ))) */
i__2 = *n;
for (i = 1; i <= *n; ++i) {
if (RWORK(i) > safe2) {
i__5 = i;
RWORK(i) = (d__1 = WORK(i).r, abs(d__1)) + (d__2 = d_imag(&
WORK(i)), abs(d__2)) + nz * eps * RWORK(i);
} else {
i__5 = i;
RWORK(i) = (d__1 = WORK(i).r, abs(d__1)) + (d__2 = d_imag(&
WORK(i)), abs(d__2)) + nz * eps * RWORK(i) + safe1;
}
/* L200: */
}
kase = 0;
L210:
zlacon_(n, &WORK(*n + 1), &WORK(1), &FERR(j), &kase);
if (kase != 0) {
if (kase == 1) {
/* Multiply by diag(W)*inv(op(A)**H). */
ztbsv_(uplo, transt, diag, n, kd, &AB(1,1), ldab, &WORK(
1), &c__1);
i__2 = *n;
for (i = 1; i <= *n; ++i) {
i__5 = i;
i__3 = i;
i__4 = i;
z__1.r = RWORK(i) * WORK(i).r, z__1.i = RWORK(i)
* WORK(i).i;
WORK(i).r = z__1.r, WORK(i).i = z__1.i;
/* L220: */
}
} else {
/* Multiply by inv(op(A))*diag(W). */
i__2 = *n;
for (i = 1; i <= *n; ++i) {
i__5 = i;
i__3 = i;
i__4 = i;
z__1.r = RWORK(i) * WORK(i).r, z__1.i = RWORK(i)
* WORK(i).i;
WORK(i).r = z__1.r, WORK(i).i = z__1.i;
/* L230: */
}
ztbsv_(uplo, transn, diag, n, kd, &AB(1,1), ldab, &WORK(
1), &c__1);
}
goto L210;
}
/* Normalize error. */
lstres = 0.;
i__2 = *n;
for (i = 1; i <= *n; ++i) {
/* Computing MAX */
i__5 = i + j * x_dim1;
d__3 = lstres, d__4 = (d__1 = X(i,j).r, abs(d__1)) + (d__2 =
d_imag(&X(i,j)), abs(d__2));
lstres = max(d__3,d__4);
/* L240: */
}
if (lstres != 0.) {
FERR(j) /= lstres;
}
/* L250: */
}
return 0;
/* End of ZTBRFS */
} /* ztbrfs_ */
/* Subroutine */ int zgbtrs_(char *trans, integer *n, integer *kl, integer *
ku, integer *nrhs, doublecomplex *ab, integer *ldab, integer *ipiv,
doublecomplex *b, integer *ldb, integer *info)
{
/* -- LAPACK routine (version 3.0) --
Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
Courant Institute, Argonne National Lab, and Rice University
September 30, 1994
Purpose
=======
ZGBTRS solves a system of linear equations
A * X = B, A**T * X = B, or A**H * X = B
with a general band matrix A using the LU factorization computed
by ZGBTRF.
Arguments
=========
TRANS (input) CHARACTER*1
Specifies the form of the system of equations.
= 'N': A * X = B (No transpose)
= 'T': A**T * X = B (Transpose)
= 'C': A**H * X = B (Conjugate transpose)
N (input) INTEGER
The order of the matrix A. N >= 0.
KL (input) INTEGER
The number of subdiagonals within the band of A. KL >= 0.
KU (input) INTEGER
The number of superdiagonals within the band of A. KU >= 0.
NRHS (input) INTEGER
The number of right hand sides, i.e., the number of columns
of the matrix B. NRHS >= 0.
AB (input) COMPLEX*16 array, dimension (LDAB,N)
Details of the LU factorization of the band matrix A, as
computed by ZGBTRF. U is stored as an upper triangular band
matrix with KL+KU superdiagonals in rows 1 to KL+KU+1, and
the multipliers used during the factorization are stored in
rows KL+KU+2 to 2*KL+KU+1.
LDAB (input) INTEGER
The leading dimension of the array AB. LDAB >= 2*KL+KU+1.
IPIV (input) INTEGER array, dimension (N)
The pivot indices; for 1 <= i <= N, row i of the matrix was
interchanged with row IPIV(i).
B (input/output) COMPLEX*16 array, dimension (LDB,NRHS)
On entry, the right hand side matrix B.
On exit, the solution matrix X.
LDB (input) INTEGER
The leading dimension of the array B. LDB >= max(1,N).
INFO (output) INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
=====================================================================
Test the input parameters.
Parameter adjustments */
/* Table of constant values */
static doublecomplex c_b1 = {1.,0.};
static integer c__1 = 1;
/* System generated locals */
integer ab_dim1, ab_offset, b_dim1, b_offset, i__1, i__2, i__3;
doublecomplex z__1;
/* Local variables */
static integer i__, j, l;
extern logical lsame_(char *, char *);
static logical lnoti;
extern /* Subroutine */ int zgemv_(char *, integer *, integer *,
doublecomplex *, doublecomplex *, integer *, doublecomplex *,
integer *, doublecomplex *, doublecomplex *, integer *),
zgeru_(integer *, integer *, doublecomplex *, doublecomplex *,
integer *, doublecomplex *, integer *, doublecomplex *, integer *)
, zswap_(integer *, doublecomplex *, integer *, doublecomplex *,
integer *), ztbsv_(char *, char *, char *, integer *, integer *,
doublecomplex *, integer *, doublecomplex *, integer *);
static integer kd, lm;
extern /* Subroutine */ int xerbla_(char *, integer *), zlacgv_(
integer *, doublecomplex *, integer *);
static logical notran;
#define b_subscr(a_1,a_2) (a_2)*b_dim1 + a_1
#define b_ref(a_1,a_2) b[b_subscr(a_1,a_2)]
#define ab_subscr(a_1,a_2) (a_2)*ab_dim1 + a_1
#define ab_ref(a_1,a_2) ab[ab_subscr(a_1,a_2)]
ab_dim1 = *ldab;
ab_offset = 1 + ab_dim1 * 1;
ab -= ab_offset;
--ipiv;
b_dim1 = *ldb;
b_offset = 1 + b_dim1 * 1;
b -= b_offset;
/* Function Body */
*info = 0;
notran = lsame_(trans, "N");
if (! notran && ! lsame_(trans, "T") && ! lsame_(
trans, "C")) {
*info = -1;
} else if (*n < 0) {
*info = -2;
} else if (*kl < 0) {
*info = -3;
} else if (*ku < 0) {
*info = -4;
} else if (*nrhs < 0) {
*info = -5;
} else if (*ldab < (*kl << 1) + *ku + 1) {
*info = -7;
} else if (*ldb < max(1,*n)) {
*info = -10;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("ZGBTRS", &i__1);
return 0;
}
/* Quick return if possible */
if (*n == 0 || *nrhs == 0) {
return 0;
}
kd = *ku + *kl + 1;
lnoti = *kl > 0;
if (notran) {
/* Solve A*X = B.
Solve L*X = B, overwriting B with X.
L is represented as a product of permutations and unit lower
triangular matrices L = P(1) * L(1) * ... * P(n-1) * L(n-1),
where each transformation L(i) is a rank-one modification of
the identity matrix. */
if (lnoti) {
i__1 = *n - 1;
for (j = 1; j <= i__1; ++j) {
/* Computing MIN */
i__2 = *kl, i__3 = *n - j;
lm = min(i__2,i__3);
l = ipiv[j];
if (l != j) {
zswap_(nrhs, &b_ref(l, 1), ldb, &b_ref(j, 1), ldb);
}
z__1.r = -1., z__1.i = 0.;
zgeru_(&lm, nrhs, &z__1, &ab_ref(kd + 1, j), &c__1, &b_ref(j,
1), ldb, &b_ref(j + 1, 1), ldb);
/* L10: */
}
}
i__1 = *nrhs;
for (i__ = 1; i__ <= i__1; ++i__) {
/* Solve U*X = B, overwriting B with X. */
i__2 = *kl + *ku;
ztbsv_("Upper", "No transpose", "Non-unit", n, &i__2, &ab[
ab_offset], ldab, &b_ref(1, i__), &c__1);
/* L20: */
}
} else if (lsame_(trans, "T")) {
/* Solve A**T * X = B. */
i__1 = *nrhs;
for (i__ = 1; i__ <= i__1; ++i__) {
/* Solve U**T * X = B, overwriting B with X. */
i__2 = *kl + *ku;
ztbsv_("Upper", "Transpose", "Non-unit", n, &i__2, &ab[ab_offset],
ldab, &b_ref(1, i__), &c__1);
/* L30: */
}
/* Solve L**T * X = B, overwriting B with X. */
if (lnoti) {
for (j = *n - 1; j >= 1; --j) {
/* Computing MIN */
i__1 = *kl, i__2 = *n - j;
lm = min(i__1,i__2);
z__1.r = -1., z__1.i = 0.;
zgemv_("Transpose", &lm, nrhs, &z__1, &b_ref(j + 1, 1), ldb, &
ab_ref(kd + 1, j), &c__1, &c_b1, &b_ref(j, 1), ldb);
l = ipiv[j];
if (l != j) {
zswap_(nrhs, &b_ref(l, 1), ldb, &b_ref(j, 1), ldb);
}
/* L40: */
}
}
} else {
/* Solve A**H * X = B. */
i__1 = *nrhs;
for (i__ = 1; i__ <= i__1; ++i__) {
/* Solve U**H * X = B, overwriting B with X. */
i__2 = *kl + *ku;
ztbsv_("Upper", "Conjugate transpose", "Non-unit", n, &i__2, &ab[
ab_offset], ldab, &b_ref(1, i__), &c__1);
/* L50: */
}
/* Solve L**H * X = B, overwriting B with X. */
if (lnoti) {
for (j = *n - 1; j >= 1; --j) {
/* Computing MIN */
i__1 = *kl, i__2 = *n - j;
lm = min(i__1,i__2);
zlacgv_(nrhs, &b_ref(j, 1), ldb);
z__1.r = -1., z__1.i = 0.;
zgemv_("Conjugate transpose", &lm, nrhs, &z__1, &b_ref(j + 1,
1), ldb, &ab_ref(kd + 1, j), &c__1, &c_b1, &b_ref(j,
1), ldb);
zlacgv_(nrhs, &b_ref(j, 1), ldb);
l = ipiv[j];
if (l != j) {
zswap_(nrhs, &b_ref(l, 1), ldb, &b_ref(j, 1), ldb);
}
/* L60: */
}
}
}
return 0;
/* End of ZGBTRS */
} /* zgbtrs_ */
/* Subroutine */ int ztbtrs_(char *uplo, char *trans, char *diag, integer *n,
integer *kd, integer *nrhs, doublecomplex *ab, integer *ldab,
doublecomplex *b, integer *ldb, integer *info)
{
/* System generated locals */
integer ab_dim1, ab_offset, b_dim1, b_offset, i__1, i__2;
/* Local variables */
integer j;
extern logical lsame_(char *, char *);
logical upper;
extern /* Subroutine */ int ztbsv_(char *, char *, char *, integer *,
integer *, doublecomplex *, integer *, doublecomplex *, integer *), xerbla_(char *, integer *);
logical nounit;
/* -- LAPACK routine (version 3.1) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* ZTBTRS solves a triangular system of the form */
/* A * X = B, A**T * X = B, or A**H * X = B, */
/* where A is a triangular band matrix of order N, and B is an */
/* N-by-NRHS matrix. A check is made to verify that A is nonsingular. */
/* Arguments */
/* ========= */
/* UPLO (input) CHARACTER*1 */
/* = 'U': A is upper triangular; */
/* = 'L': A is lower triangular. */
/* TRANS (input) CHARACTER*1 */
/* Specifies the form of the system of equations: */
/* = 'N': A * X = B (No transpose) */
/* = 'T': A**T * X = B (Transpose) */
/* = 'C': A**H * X = B (Conjugate transpose) */
/* DIAG (input) CHARACTER*1 */
/* = 'N': A is non-unit triangular; */
/* = 'U': A is unit triangular. */
/* N (input) INTEGER */
/* The order of the matrix A. N >= 0. */
/* KD (input) INTEGER */
/* The number of superdiagonals or subdiagonals of the */
/* triangular band matrix A. KD >= 0. */
/* NRHS (input) INTEGER */
/* The number of right hand sides, i.e., the number of columns */
/* of the matrix B. NRHS >= 0. */
/* AB (input) COMPLEX*16 array, dimension (LDAB,N) */
/* The upper or lower triangular band matrix A, stored in the */
/* first kd+1 rows of AB. The j-th column of A is stored */
/* in the j-th column of the array AB as follows: */
/* if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j; */
/* if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j<=i<=min(n,j+kd). */
/* If DIAG = 'U', the diagonal elements of A are not referenced */
/* and are assumed to be 1. */
/* LDAB (input) INTEGER */
/* The leading dimension of the array AB. LDAB >= KD+1. */
/* B (input/output) COMPLEX*16 array, dimension (LDB,NRHS) */
/* On entry, the right hand side matrix B. */
/* On exit, if INFO = 0, the solution matrix X. */
/* LDB (input) INTEGER */
/* The leading dimension of the array B. LDB >= max(1,N). */
/* INFO (output) INTEGER */
/* = 0: successful exit */
/* < 0: if INFO = -i, the i-th argument had an illegal value */
/* > 0: if INFO = i, the i-th diagonal element of A is zero, */
/* indicating that the matrix is singular and the */
/* solutions X have not been computed. */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Test the input parameters. */
/* Parameter adjustments */
ab_dim1 = *ldab;
ab_offset = 1 + ab_dim1;
ab -= ab_offset;
b_dim1 = *ldb;
b_offset = 1 + b_dim1;
b -= b_offset;
/* Function Body */
*info = 0;
nounit = lsame_(diag, "N");
upper = lsame_(uplo, "U");
if (! upper && ! lsame_(uplo, "L")) {
*info = -1;
} else if (! lsame_(trans, "N") && ! lsame_(trans,
"T") && ! lsame_(trans, "C")) {
*info = -2;
} else if (! nounit && ! lsame_(diag, "U")) {
*info = -3;
} else if (*n < 0) {
*info = -4;
} else if (*kd < 0) {
*info = -5;
} else if (*nrhs < 0) {
*info = -6;
} else if (*ldab < *kd + 1) {
*info = -8;
} else if (*ldb < max(1,*n)) {
*info = -10;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("ZTBTRS", &i__1);
return 0;
}
/* Quick return if possible */
if (*n == 0) {
return 0;
}
/* Check for singularity. */
if (nounit) {
if (upper) {
i__1 = *n;
for (*info = 1; *info <= i__1; ++(*info)) {
i__2 = *kd + 1 + *info * ab_dim1;
if (ab[i__2].r == 0. && ab[i__2].i == 0.) {
return 0;
}
/* L10: */
}
} else {
i__1 = *n;
for (*info = 1; *info <= i__1; ++(*info)) {
i__2 = *info * ab_dim1 + 1;
if (ab[i__2].r == 0. && ab[i__2].i == 0.) {
return 0;
}
/* L20: */
}
}
}
*info = 0;
/* Solve A * X = B, A**T * X = B, or A**H * X = B. */
i__1 = *nrhs;
for (j = 1; j <= i__1; ++j) {
ztbsv_(uplo, trans, diag, n, kd, &ab[ab_offset], ldab, &b[j * b_dim1
+ 1], &c__1);
/* L30: */
}
return 0;
/* End of ZTBTRS */
} /* ztbtrs_ */
/* Subroutine */
int zlatbs_(char *uplo, char *trans, char *diag, char * normin, integer *n, integer *kd, doublecomplex *ab, integer *ldab, doublecomplex *x, doublereal *scale, doublereal *cnorm, integer *info)
{
/* System generated locals */
integer ab_dim1, ab_offset, i__1, i__2, i__3, i__4, i__5;
doublereal d__1, d__2, d__3, d__4;
doublecomplex z__1, z__2, z__3, z__4;
/* Builtin functions */
double d_imag(doublecomplex *);
void d_cnjg(doublecomplex *, doublecomplex *);
/* Local variables */
integer i__, j;
doublereal xj, rec, tjj;
integer jinc, jlen;
doublereal xbnd;
integer imax;
doublereal tmax;
doublecomplex tjjs;
doublereal xmax, grow;
extern /* Subroutine */
int dscal_(integer *, doublereal *, doublereal *, integer *);
integer maind;
extern logical lsame_(char *, char *);
doublereal tscal;
doublecomplex uscal;
integer jlast;
doublecomplex csumj;
extern /* Double Complex */
VOID zdotc_f2c_(doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *);
logical upper;
extern /* Double Complex */
VOID zdotu_f2c_(doublecomplex *, integer *, doublecomplex *, integer *, doublecomplex *, integer *);
extern /* Subroutine */
int ztbsv_(char *, char *, char *, integer *, integer *, doublecomplex *, integer *, doublecomplex *, integer *), zaxpy_(integer *, doublecomplex *, doublecomplex *, integer *, doublecomplex *, integer *), dlabad_( doublereal *, doublereal *);
extern doublereal dlamch_(char *);
extern integer idamax_(integer *, doublereal *, integer *);
extern /* Subroutine */
int xerbla_(char *, integer *), zdscal_( integer *, doublereal *, doublecomplex *, integer *);
doublereal bignum;
extern integer izamax_(integer *, doublecomplex *, integer *);
extern /* Double Complex */
VOID zladiv_(doublecomplex *, doublecomplex *, doublecomplex *);
logical notran;
integer jfirst;
extern doublereal dzasum_(integer *, doublecomplex *, integer *);
doublereal smlnum;
logical nounit;
/* -- 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 .. */
/* .. */
/* .. Statement Functions .. */
/* .. */
/* .. Statement Function definitions .. */
/* .. */
/* .. Executable Statements .. */
/* Parameter adjustments */
ab_dim1 = *ldab;
ab_offset = 1 + ab_dim1;
ab -= ab_offset;
--x;
--cnorm;
/* Function Body */
*info = 0;
upper = lsame_(uplo, "U");
notran = lsame_(trans, "N");
nounit = lsame_(diag, "N");
/* Test the input parameters. */
if (! upper && ! lsame_(uplo, "L"))
{
*info = -1;
}
else if (! notran && ! lsame_(trans, "T") && ! lsame_(trans, "C"))
{
*info = -2;
}
else if (! nounit && ! lsame_(diag, "U"))
{
*info = -3;
}
else if (! lsame_(normin, "Y") && ! lsame_(normin, "N"))
{
*info = -4;
}
else if (*n < 0)
{
*info = -5;
}
else if (*kd < 0)
{
*info = -6;
}
else if (*ldab < *kd + 1)
{
*info = -8;
}
if (*info != 0)
{
i__1 = -(*info);
xerbla_("ZLATBS", &i__1);
return 0;
}
/* Quick return if possible */
if (*n == 0)
{
return 0;
}
/* Determine machine dependent parameters to control overflow. */
smlnum = dlamch_("Safe minimum");
bignum = 1. / smlnum;
dlabad_(&smlnum, &bignum);
smlnum /= dlamch_("Precision");
bignum = 1. / smlnum;
*scale = 1.;
if (lsame_(normin, "N"))
{
/* Compute the 1-norm of each column, not including the diagonal. */
if (upper)
{
/* A is upper triangular. */
i__1 = *n;
for (j = 1;
j <= i__1;
++j)
{
/* Computing MIN */
i__2 = *kd;
i__3 = j - 1; // , expr subst
jlen = min(i__2,i__3);
cnorm[j] = dzasum_(&jlen, &ab[*kd + 1 - jlen + j * ab_dim1], & c__1);
/* L10: */
}
}
else
{
/* A is lower triangular. */
i__1 = *n;
for (j = 1;
j <= i__1;
++j)
{
/* Computing MIN */
i__2 = *kd;
i__3 = *n - j; // , expr subst
jlen = min(i__2,i__3);
if (jlen > 0)
{
cnorm[j] = dzasum_(&jlen, &ab[j * ab_dim1 + 2], &c__1);
}
else
{
cnorm[j] = 0.;
}
/* L20: */
}
}
}
/* Scale the column norms by TSCAL if the maximum element in CNORM is */
/* greater than BIGNUM/2. */
imax = idamax_(n, &cnorm[1], &c__1);
tmax = cnorm[imax];
if (tmax <= bignum * .5)
{
tscal = 1.;
}
else
{
tscal = .5 / (smlnum * tmax);
dscal_(n, &tscal, &cnorm[1], &c__1);
}
/* Compute a bound on the computed solution vector to see if the */
/* Level 2 BLAS routine ZTBSV can be used. */
xmax = 0.;
i__1 = *n;
for (j = 1;
j <= i__1;
++j)
{
/* Computing MAX */
i__2 = j;
d__3 = xmax;
d__4 = (d__1 = x[i__2].r / 2., abs(d__1)) + (d__2 = d_imag(&x[j]) / 2., abs(d__2)); // , expr subst
xmax = max(d__3,d__4);
/* L30: */
}
xbnd = xmax;
if (notran)
{
/* Compute the growth in A * x = b. */
if (upper)
{
jfirst = *n;
jlast = 1;
jinc = -1;
maind = *kd + 1;
}
else
{
jfirst = 1;
jlast = *n;
jinc = 1;
maind = 1;
}
if (tscal != 1.)
{
grow = 0.;
goto L60;
}
if (nounit)
{
/* A is non-unit triangular. */
/* Compute GROW = 1/G(j) and XBND = 1/M(j). */
/* Initially, G(0) = max{
x(i), i=1,...,n}
. */
grow = .5 / max(xbnd,smlnum);
xbnd = grow;
i__1 = jlast;
i__2 = jinc;
for (j = jfirst;
i__2 < 0 ? j >= i__1 : j <= i__1;
j += i__2)
{
/* Exit the loop if the growth factor is too small. */
if (grow <= smlnum)
{
goto L60;
}
i__3 = maind + j * ab_dim1;
tjjs.r = ab[i__3].r;
tjjs.i = ab[i__3].i; // , expr subst
tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs( d__2));
if (tjj >= smlnum)
{
/* M(j) = G(j-1) / abs(A(j,j)) */
/* Computing MIN */
d__1 = xbnd;
d__2 = min(1.,tjj) * grow; // , expr subst
xbnd = min(d__1,d__2);
}
else
{
/* M(j) could overflow, set XBND to 0. */
xbnd = 0.;
}
if (tjj + cnorm[j] >= smlnum)
{
/* G(j) = G(j-1)*( 1 + CNORM(j) / abs(A(j,j)) ) */
grow *= tjj / (tjj + cnorm[j]);
}
else
{
/* G(j) could overflow, set GROW to 0. */
grow = 0.;
}
/* L40: */
}
grow = xbnd;
}
else
{
/* A is unit triangular. */
/* Compute GROW = 1/G(j), where G(0) = max{
x(i), i=1,...,n}
. */
/* Computing MIN */
d__1 = 1.;
d__2 = .5 / max(xbnd,smlnum); // , expr subst
grow = min(d__1,d__2);
i__2 = jlast;
i__1 = jinc;
for (j = jfirst;
i__1 < 0 ? j >= i__2 : j <= i__2;
j += i__1)
{
/* Exit the loop if the growth factor is too small. */
if (grow <= smlnum)
{
goto L60;
}
/* G(j) = G(j-1)*( 1 + CNORM(j) ) */
grow *= 1. / (cnorm[j] + 1.);
/* L50: */
}
}
L60:
;
}
else
{
/* Compute the growth in A**T * x = b or A**H * x = b. */
if (upper)
{
jfirst = 1;
jlast = *n;
jinc = 1;
maind = *kd + 1;
}
else
{
jfirst = *n;
jlast = 1;
jinc = -1;
maind = 1;
}
if (tscal != 1.)
{
grow = 0.;
goto L90;
}
if (nounit)
{
/* A is non-unit triangular. */
/* Compute GROW = 1/G(j) and XBND = 1/M(j). */
/* Initially, M(0) = max{
x(i), i=1,...,n}
. */
grow = .5 / max(xbnd,smlnum);
xbnd = grow;
i__1 = jlast;
i__2 = jinc;
for (j = jfirst;
i__2 < 0 ? j >= i__1 : j <= i__1;
j += i__2)
{
/* Exit the loop if the growth factor is too small. */
if (grow <= smlnum)
{
goto L90;
}
/* G(j) = max( G(j-1), M(j-1)*( 1 + CNORM(j) ) ) */
xj = cnorm[j] + 1.;
/* Computing MIN */
d__1 = grow;
d__2 = xbnd / xj; // , expr subst
grow = min(d__1,d__2);
i__3 = maind + j * ab_dim1;
tjjs.r = ab[i__3].r;
tjjs.i = ab[i__3].i; // , expr subst
tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs( d__2));
if (tjj >= smlnum)
{
/* M(j) = M(j-1)*( 1 + CNORM(j) ) / abs(A(j,j)) */
if (xj > tjj)
{
xbnd *= tjj / xj;
}
}
else
{
/* M(j) could overflow, set XBND to 0. */
xbnd = 0.;
}
/* L70: */
}
grow = min(grow,xbnd);
}
else
{
/* A is unit triangular. */
/* Compute GROW = 1/G(j), where G(0) = max{
x(i), i=1,...,n}
. */
/* Computing MIN */
d__1 = 1.;
d__2 = .5 / max(xbnd,smlnum); // , expr subst
grow = min(d__1,d__2);
i__2 = jlast;
i__1 = jinc;
for (j = jfirst;
i__1 < 0 ? j >= i__2 : j <= i__2;
j += i__1)
{
/* Exit the loop if the growth factor is too small. */
if (grow <= smlnum)
{
goto L90;
}
/* G(j) = ( 1 + CNORM(j) )*G(j-1) */
xj = cnorm[j] + 1.;
grow /= xj;
/* L80: */
}
}
L90:
;
}
if (grow * tscal > smlnum)
{
/* Use the Level 2 BLAS solve if the reciprocal of the bound on */
/* elements of X is not too small. */
ztbsv_(uplo, trans, diag, n, kd, &ab[ab_offset], ldab, &x[1], &c__1);
}
else
{
/* Use a Level 1 BLAS solve, scaling intermediate results. */
if (xmax > bignum * .5)
{
/* Scale X so that its components are less than or equal to */
/* BIGNUM in absolute value. */
*scale = bignum * .5 / xmax;
zdscal_(n, scale, &x[1], &c__1);
xmax = bignum;
}
else
{
xmax *= 2.;
}
if (notran)
{
/* Solve A * x = b */
i__1 = jlast;
i__2 = jinc;
for (j = jfirst;
i__2 < 0 ? j >= i__1 : j <= i__1;
j += i__2)
{
/* Compute x(j) = b(j) / A(j,j), scaling x if necessary. */
i__3 = j;
xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]), abs(d__2));
if (nounit)
{
i__3 = maind + j * ab_dim1;
z__1.r = tscal * ab[i__3].r;
z__1.i = tscal * ab[i__3].i; // , expr subst
tjjs.r = z__1.r;
tjjs.i = z__1.i; // , expr subst
}
else
{
tjjs.r = tscal;
tjjs.i = 0.; // , expr subst
if (tscal == 1.)
{
goto L110;
}
}
tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs( d__2));
if (tjj > smlnum)
{
/* abs(A(j,j)) > SMLNUM: */
if (tjj < 1.)
{
if (xj > tjj * bignum)
{
/* Scale x by 1/b(j). */
rec = 1. / xj;
zdscal_(n, &rec, &x[1], &c__1);
*scale *= rec;
xmax *= rec;
}
}
i__3 = j;
zladiv_(&z__1, &x[j], &tjjs);
x[i__3].r = z__1.r;
x[i__3].i = z__1.i; // , expr subst
i__3 = j;
xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]) , abs(d__2));
}
else if (tjj > 0.)
{
/* 0 < abs(A(j,j)) <= SMLNUM: */
if (xj > tjj * bignum)
{
/* Scale x by (1/abs(x(j)))*abs(A(j,j))*BIGNUM */
/* to avoid overflow when dividing by A(j,j). */
rec = tjj * bignum / xj;
if (cnorm[j] > 1.)
{
/* Scale by 1/CNORM(j) to avoid overflow when */
/* multiplying x(j) times column j. */
rec /= cnorm[j];
}
zdscal_(n, &rec, &x[1], &c__1);
*scale *= rec;
xmax *= rec;
}
i__3 = j;
zladiv_(&z__1, &x[j], &tjjs);
x[i__3].r = z__1.r;
x[i__3].i = z__1.i; // , expr subst
i__3 = j;
xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]) , abs(d__2));
}
else
{
/* A(j,j) = 0: Set x(1:n) = 0, x(j) = 1, and */
/* scale = 0, and compute a solution to A*x = 0. */
i__3 = *n;
for (i__ = 1;
i__ <= i__3;
++i__)
{
i__4 = i__;
x[i__4].r = 0.;
x[i__4].i = 0.; // , expr subst
/* L100: */
}
i__3 = j;
x[i__3].r = 1.;
x[i__3].i = 0.; // , expr subst
xj = 1.;
*scale = 0.;
xmax = 0.;
}
L110: /* Scale x if necessary to avoid overflow when adding a */
/* multiple of column j of A. */
if (xj > 1.)
{
rec = 1. / xj;
if (cnorm[j] > (bignum - xmax) * rec)
{
/* Scale x by 1/(2*abs(x(j))). */
rec *= .5;
zdscal_(n, &rec, &x[1], &c__1);
*scale *= rec;
}
}
else if (xj * cnorm[j] > bignum - xmax)
{
/* Scale x by 1/2. */
zdscal_(n, &c_b36, &x[1], &c__1);
*scale *= .5;
}
if (upper)
{
if (j > 1)
{
/* Compute the update */
/* x(max(1,j-kd):j-1) := x(max(1,j-kd):j-1) - */
/* x(j)* A(max(1,j-kd):j-1,j) */
/* Computing MIN */
i__3 = *kd;
i__4 = j - 1; // , expr subst
jlen = min(i__3,i__4);
i__3 = j;
z__2.r = -x[i__3].r;
z__2.i = -x[i__3].i; // , expr subst
z__1.r = tscal * z__2.r;
z__1.i = tscal * z__2.i; // , expr subst
zaxpy_(&jlen, &z__1, &ab[*kd + 1 - jlen + j * ab_dim1] , &c__1, &x[j - jlen], &c__1);
i__3 = j - 1;
i__ = izamax_(&i__3, &x[1], &c__1);
i__3 = i__;
xmax = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag( &x[i__]), abs(d__2));
}
}
else if (j < *n)
{
/* Compute the update */
/* x(j+1:min(j+kd,n)) := x(j+1:min(j+kd,n)) - */
/* x(j) * A(j+1:min(j+kd,n),j) */
/* Computing MIN */
i__3 = *kd;
i__4 = *n - j; // , expr subst
jlen = min(i__3,i__4);
if (jlen > 0)
{
i__3 = j;
z__2.r = -x[i__3].r;
z__2.i = -x[i__3].i; // , expr subst
z__1.r = tscal * z__2.r;
z__1.i = tscal * z__2.i; // , expr subst
zaxpy_(&jlen, &z__1, &ab[j * ab_dim1 + 2], &c__1, &x[ j + 1], &c__1);
}
i__3 = *n - j;
i__ = j + izamax_(&i__3, &x[j + 1], &c__1);
i__3 = i__;
xmax = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[ i__]), abs(d__2));
}
/* L120: */
}
}
else if (lsame_(trans, "T"))
{
/* Solve A**T * x = b */
i__2 = jlast;
i__1 = jinc;
for (j = jfirst;
i__1 < 0 ? j >= i__2 : j <= i__2;
j += i__1)
{
/* Compute x(j) = b(j) - sum A(k,j)*x(k). */
/* k<>j */
i__3 = j;
xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]), abs(d__2));
uscal.r = tscal;
uscal.i = 0.; // , expr subst
rec = 1. / max(xmax,1.);
if (cnorm[j] > (bignum - xj) * rec)
{
/* If x(j) could overflow, scale x by 1/(2*XMAX). */
rec *= .5;
if (nounit)
{
i__3 = maind + j * ab_dim1;
z__1.r = tscal * ab[i__3].r;
z__1.i = tscal * ab[i__3] .i; // , expr subst
tjjs.r = z__1.r;
tjjs.i = z__1.i; // , expr subst
}
else
{
tjjs.r = tscal;
tjjs.i = 0.; // , expr subst
}
tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs(d__2));
if (tjj > 1.)
{
/* Divide by A(j,j) when scaling x if A(j,j) > 1. */
/* Computing MIN */
d__1 = 1.;
d__2 = rec * tjj; // , expr subst
rec = min(d__1,d__2);
zladiv_(&z__1, &uscal, &tjjs);
uscal.r = z__1.r;
uscal.i = z__1.i; // , expr subst
}
if (rec < 1.)
{
zdscal_(n, &rec, &x[1], &c__1);
*scale *= rec;
xmax *= rec;
}
}
csumj.r = 0.;
csumj.i = 0.; // , expr subst
if (uscal.r == 1. && uscal.i == 0.)
{
/* If the scaling needed for A in the dot product is 1, */
/* call ZDOTU to perform the dot product. */
if (upper)
{
/* Computing MIN */
i__3 = *kd;
i__4 = j - 1; // , expr subst
jlen = min(i__3,i__4);
zdotu_f2c_(&z__1, &jlen, &ab[*kd + 1 - jlen + j * ab_dim1] , &c__1, &x[j - jlen], &c__1);
csumj.r = z__1.r;
csumj.i = z__1.i; // , expr subst
}
else
{
/* Computing MIN */
i__3 = *kd;
i__4 = *n - j; // , expr subst
jlen = min(i__3,i__4);
if (jlen > 1)
{
zdotu_f2c_(&z__1, &jlen, &ab[j * ab_dim1 + 2], &c__1, &x[j + 1], &c__1);
csumj.r = z__1.r;
csumj.i = z__1.i; // , expr subst
}
}
}
else
{
/* Otherwise, use in-line code for the dot product. */
if (upper)
{
/* Computing MIN */
i__3 = *kd;
i__4 = j - 1; // , expr subst
jlen = min(i__3,i__4);
i__3 = jlen;
for (i__ = 1;
i__ <= i__3;
++i__)
{
i__4 = *kd + i__ - jlen + j * ab_dim1;
z__3.r = ab[i__4].r * uscal.r - ab[i__4].i * uscal.i;
z__3.i = ab[i__4].r * uscal.i + ab[i__4].i * uscal.r; // , expr subst
i__5 = j - jlen - 1 + i__;
z__2.r = z__3.r * x[i__5].r - z__3.i * x[i__5].i;
z__2.i = z__3.r * x[i__5].i + z__3.i * x[ i__5].r; // , expr subst
z__1.r = csumj.r + z__2.r;
z__1.i = csumj.i + z__2.i; // , expr subst
csumj.r = z__1.r;
csumj.i = z__1.i; // , expr subst
/* L130: */
}
}
else
{
/* Computing MIN */
i__3 = *kd;
i__4 = *n - j; // , expr subst
jlen = min(i__3,i__4);
i__3 = jlen;
for (i__ = 1;
i__ <= i__3;
++i__)
{
i__4 = i__ + 1 + j * ab_dim1;
z__3.r = ab[i__4].r * uscal.r - ab[i__4].i * uscal.i;
z__3.i = ab[i__4].r * uscal.i + ab[i__4].i * uscal.r; // , expr subst
i__5 = j + i__;
z__2.r = z__3.r * x[i__5].r - z__3.i * x[i__5].i;
z__2.i = z__3.r * x[i__5].i + z__3.i * x[ i__5].r; // , expr subst
z__1.r = csumj.r + z__2.r;
z__1.i = csumj.i + z__2.i; // , expr subst
csumj.r = z__1.r;
csumj.i = z__1.i; // , expr subst
/* L140: */
}
}
}
z__1.r = tscal;
z__1.i = 0.; // , expr subst
if (uscal.r == z__1.r && uscal.i == z__1.i)
{
/* Compute x(j) := ( x(j) - CSUMJ ) / A(j,j) if 1/A(j,j) */
/* was not used to scale the dotproduct. */
i__3 = j;
i__4 = j;
z__1.r = x[i__4].r - csumj.r;
z__1.i = x[i__4].i - csumj.i; // , expr subst
x[i__3].r = z__1.r;
x[i__3].i = z__1.i; // , expr subst
i__3 = j;
xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]) , abs(d__2));
if (nounit)
{
/* Compute x(j) = x(j) / A(j,j), scaling if necessary. */
i__3 = maind + j * ab_dim1;
z__1.r = tscal * ab[i__3].r;
z__1.i = tscal * ab[i__3] .i; // , expr subst
tjjs.r = z__1.r;
tjjs.i = z__1.i; // , expr subst
}
else
{
tjjs.r = tscal;
tjjs.i = 0.; // , expr subst
if (tscal == 1.)
{
goto L160;
}
}
tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs(d__2));
if (tjj > smlnum)
{
/* abs(A(j,j)) > SMLNUM: */
if (tjj < 1.)
{
if (xj > tjj * bignum)
{
/* Scale X by 1/abs(x(j)). */
rec = 1. / xj;
zdscal_(n, &rec, &x[1], &c__1);
*scale *= rec;
xmax *= rec;
}
}
i__3 = j;
zladiv_(&z__1, &x[j], &tjjs);
x[i__3].r = z__1.r;
x[i__3].i = z__1.i; // , expr subst
}
else if (tjj > 0.)
{
/* 0 < abs(A(j,j)) <= SMLNUM: */
if (xj > tjj * bignum)
{
/* Scale x by (1/abs(x(j)))*abs(A(j,j))*BIGNUM. */
rec = tjj * bignum / xj;
zdscal_(n, &rec, &x[1], &c__1);
*scale *= rec;
xmax *= rec;
}
i__3 = j;
zladiv_(&z__1, &x[j], &tjjs);
x[i__3].r = z__1.r;
x[i__3].i = z__1.i; // , expr subst
}
else
{
/* A(j,j) = 0: Set x(1:n) = 0, x(j) = 1, and */
/* scale = 0 and compute a solution to A**T *x = 0. */
i__3 = *n;
for (i__ = 1;
i__ <= i__3;
++i__)
{
i__4 = i__;
x[i__4].r = 0.;
x[i__4].i = 0.; // , expr subst
/* L150: */
}
i__3 = j;
x[i__3].r = 1.;
x[i__3].i = 0.; // , expr subst
*scale = 0.;
xmax = 0.;
}
L160:
;
}
else
{
/* Compute x(j) := x(j) / A(j,j) - CSUMJ if the dot */
/* product has already been divided by 1/A(j,j). */
i__3 = j;
zladiv_(&z__2, &x[j], &tjjs);
z__1.r = z__2.r - csumj.r;
z__1.i = z__2.i - csumj.i; // , expr subst
x[i__3].r = z__1.r;
x[i__3].i = z__1.i; // , expr subst
}
/* Computing MAX */
i__3 = j;
d__3 = xmax;
d__4 = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]), abs(d__2)); // , expr subst
xmax = max(d__3,d__4);
/* L170: */
}
}
else
{
/* Solve A**H * x = b */
i__1 = jlast;
i__2 = jinc;
for (j = jfirst;
i__2 < 0 ? j >= i__1 : j <= i__1;
j += i__2)
{
/* Compute x(j) = b(j) - sum A(k,j)*x(k). */
/* k<>j */
i__3 = j;
xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]), abs(d__2));
uscal.r = tscal;
uscal.i = 0.; // , expr subst
rec = 1. / max(xmax,1.);
if (cnorm[j] > (bignum - xj) * rec)
{
/* If x(j) could overflow, scale x by 1/(2*XMAX). */
rec *= .5;
if (nounit)
{
d_cnjg(&z__2, &ab[maind + j * ab_dim1]);
z__1.r = tscal * z__2.r;
z__1.i = tscal * z__2.i; // , expr subst
tjjs.r = z__1.r;
tjjs.i = z__1.i; // , expr subst
}
else
{
tjjs.r = tscal;
tjjs.i = 0.; // , expr subst
}
tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs(d__2));
if (tjj > 1.)
{
/* Divide by A(j,j) when scaling x if A(j,j) > 1. */
/* Computing MIN */
d__1 = 1.;
d__2 = rec * tjj; // , expr subst
rec = min(d__1,d__2);
zladiv_(&z__1, &uscal, &tjjs);
uscal.r = z__1.r;
uscal.i = z__1.i; // , expr subst
}
if (rec < 1.)
{
zdscal_(n, &rec, &x[1], &c__1);
*scale *= rec;
xmax *= rec;
}
}
csumj.r = 0.;
csumj.i = 0.; // , expr subst
if (uscal.r == 1. && uscal.i == 0.)
{
/* If the scaling needed for A in the dot product is 1, */
/* call ZDOTC to perform the dot product. */
if (upper)
{
/* Computing MIN */
i__3 = *kd;
i__4 = j - 1; // , expr subst
jlen = min(i__3,i__4);
zdotc_f2c_(&z__1, &jlen, &ab[*kd + 1 - jlen + j * ab_dim1] , &c__1, &x[j - jlen], &c__1);
csumj.r = z__1.r;
csumj.i = z__1.i; // , expr subst
}
else
{
/* Computing MIN */
i__3 = *kd;
i__4 = *n - j; // , expr subst
jlen = min(i__3,i__4);
if (jlen > 1)
{
zdotc_f2c_(&z__1, &jlen, &ab[j * ab_dim1 + 2], &c__1, &x[j + 1], &c__1);
csumj.r = z__1.r;
csumj.i = z__1.i; // , expr subst
}
}
}
else
{
/* Otherwise, use in-line code for the dot product. */
if (upper)
{
/* Computing MIN */
i__3 = *kd;
i__4 = j - 1; // , expr subst
jlen = min(i__3,i__4);
i__3 = jlen;
for (i__ = 1;
i__ <= i__3;
++i__)
{
d_cnjg(&z__4, &ab[*kd + i__ - jlen + j * ab_dim1]) ;
z__3.r = z__4.r * uscal.r - z__4.i * uscal.i;
z__3.i = z__4.r * uscal.i + z__4.i * uscal.r; // , expr subst
i__4 = j - jlen - 1 + i__;
z__2.r = z__3.r * x[i__4].r - z__3.i * x[i__4].i;
z__2.i = z__3.r * x[i__4].i + z__3.i * x[ i__4].r; // , expr subst
z__1.r = csumj.r + z__2.r;
z__1.i = csumj.i + z__2.i; // , expr subst
csumj.r = z__1.r;
csumj.i = z__1.i; // , expr subst
/* L180: */
}
}
else
{
/* Computing MIN */
i__3 = *kd;
i__4 = *n - j; // , expr subst
jlen = min(i__3,i__4);
i__3 = jlen;
for (i__ = 1;
i__ <= i__3;
++i__)
{
d_cnjg(&z__4, &ab[i__ + 1 + j * ab_dim1]);
z__3.r = z__4.r * uscal.r - z__4.i * uscal.i;
z__3.i = z__4.r * uscal.i + z__4.i * uscal.r; // , expr subst
i__4 = j + i__;
z__2.r = z__3.r * x[i__4].r - z__3.i * x[i__4].i;
z__2.i = z__3.r * x[i__4].i + z__3.i * x[ i__4].r; // , expr subst
z__1.r = csumj.r + z__2.r;
z__1.i = csumj.i + z__2.i; // , expr subst
csumj.r = z__1.r;
csumj.i = z__1.i; // , expr subst
/* L190: */
}
}
}
z__1.r = tscal;
z__1.i = 0.; // , expr subst
if (uscal.r == z__1.r && uscal.i == z__1.i)
{
/* Compute x(j) := ( x(j) - CSUMJ ) / A(j,j) if 1/A(j,j) */
/* was not used to scale the dotproduct. */
i__3 = j;
i__4 = j;
z__1.r = x[i__4].r - csumj.r;
z__1.i = x[i__4].i - csumj.i; // , expr subst
x[i__3].r = z__1.r;
x[i__3].i = z__1.i; // , expr subst
i__3 = j;
xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]) , abs(d__2));
if (nounit)
{
/* Compute x(j) = x(j) / A(j,j), scaling if necessary. */
d_cnjg(&z__2, &ab[maind + j * ab_dim1]);
z__1.r = tscal * z__2.r;
z__1.i = tscal * z__2.i; // , expr subst
tjjs.r = z__1.r;
tjjs.i = z__1.i; // , expr subst
}
else
{
tjjs.r = tscal;
tjjs.i = 0.; // , expr subst
if (tscal == 1.)
{
goto L210;
}
}
tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs(d__2));
if (tjj > smlnum)
{
/* abs(A(j,j)) > SMLNUM: */
if (tjj < 1.)
{
if (xj > tjj * bignum)
{
/* Scale X by 1/abs(x(j)). */
rec = 1. / xj;
zdscal_(n, &rec, &x[1], &c__1);
*scale *= rec;
xmax *= rec;
}
}
i__3 = j;
zladiv_(&z__1, &x[j], &tjjs);
x[i__3].r = z__1.r;
x[i__3].i = z__1.i; // , expr subst
}
else if (tjj > 0.)
{
/* 0 < abs(A(j,j)) <= SMLNUM: */
if (xj > tjj * bignum)
{
/* Scale x by (1/abs(x(j)))*abs(A(j,j))*BIGNUM. */
rec = tjj * bignum / xj;
zdscal_(n, &rec, &x[1], &c__1);
*scale *= rec;
xmax *= rec;
}
i__3 = j;
zladiv_(&z__1, &x[j], &tjjs);
x[i__3].r = z__1.r;
x[i__3].i = z__1.i; // , expr subst
}
else
{
/* A(j,j) = 0: Set x(1:n) = 0, x(j) = 1, and */
/* scale = 0 and compute a solution to A**H *x = 0. */
i__3 = *n;
for (i__ = 1;
i__ <= i__3;
++i__)
{
i__4 = i__;
x[i__4].r = 0.;
x[i__4].i = 0.; // , expr subst
/* L200: */
}
i__3 = j;
x[i__3].r = 1.;
x[i__3].i = 0.; // , expr subst
*scale = 0.;
xmax = 0.;
}
L210:
;
}
else
{
/* Compute x(j) := x(j) / A(j,j) - CSUMJ if the dot */
/* product has already been divided by 1/A(j,j). */
i__3 = j;
zladiv_(&z__2, &x[j], &tjjs);
z__1.r = z__2.r - csumj.r;
z__1.i = z__2.i - csumj.i; // , expr subst
x[i__3].r = z__1.r;
x[i__3].i = z__1.i; // , expr subst
}
/* Computing MAX */
i__3 = j;
d__3 = xmax;
d__4 = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]), abs(d__2)); // , expr subst
xmax = max(d__3,d__4);
/* L220: */
}
}
*scale /= tscal;
}
/* Scale the column norms by 1/TSCAL for return. */
if (tscal != 1.)
{
d__1 = 1. / tscal;
dscal_(n, &d__1, &cnorm[1], &c__1);
}
return 0;
/* End of ZLATBS */
}
/* Subroutine */ int zgbtrs_(char *trans, integer *n, integer *kl, integer *
ku, integer *nrhs, doublecomplex *ab, integer *ldab, integer *ipiv,
doublecomplex *b, integer *ldb, integer *info)
{
/* System generated locals */
integer ab_dim1, ab_offset, b_dim1, b_offset, i__1, i__2, i__3;
doublecomplex z__1;
/* Local variables */
integer i__, j, l, kd, lm;
extern logical lsame_(char *, char *);
logical lnoti;
extern /* Subroutine */ int zgemv_(char *, integer *, integer *,
doublecomplex *, doublecomplex *, integer *, doublecomplex *,
integer *, doublecomplex *, doublecomplex *, integer *),
zgeru_(integer *, integer *, doublecomplex *, doublecomplex *,
integer *, doublecomplex *, integer *, doublecomplex *, integer *)
, zswap_(integer *, doublecomplex *, integer *, doublecomplex *,
integer *), ztbsv_(char *, char *, char *, integer *, integer *,
doublecomplex *, integer *, doublecomplex *, integer *), xerbla_(char *, integer *), zlacgv_(
integer *, doublecomplex *, integer *);
logical notran;
/* -- LAPACK routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* ZGBTRS solves a system of linear equations */
/* A * X = B, A**T * X = B, or A**H * X = B */
/* with a general band matrix A using the LU factorization computed */
/* by ZGBTRF. */
/* Arguments */
/* ========= */
/* TRANS (input) CHARACTER*1 */
/* Specifies the form of the system of equations. */
/* = 'N': A * X = B (No transpose) */
/* = 'T': A**T * X = B (Transpose) */
/* = 'C': A**H * X = B (Conjugate transpose) */
/* N (input) INTEGER */
/* The order of the matrix A. N >= 0. */
/* KL (input) INTEGER */
/* The number of subdiagonals within the band of A. KL >= 0. */
/* KU (input) INTEGER */
/* The number of superdiagonals within the band of A. KU >= 0. */
/* NRHS (input) INTEGER */
/* The number of right hand sides, i.e., the number of columns */
/* of the matrix B. NRHS >= 0. */
/* AB (input) COMPLEX*16 array, dimension (LDAB,N) */
/* Details of the LU factorization of the band matrix A, as */
/* computed by ZGBTRF. U is stored as an upper triangular band */
/* matrix with KL+KU superdiagonals in rows 1 to KL+KU+1, and */
/* the multipliers used during the factorization are stored in */
/* rows KL+KU+2 to 2*KL+KU+1. */
/* LDAB (input) INTEGER */
/* The leading dimension of the array AB. LDAB >= 2*KL+KU+1. */
/* IPIV (input) INTEGER array, dimension (N) */
/* The pivot indices; for 1 <= i <= N, row i of the matrix was */
/* interchanged with row IPIV(i). */
/* B (input/output) COMPLEX*16 array, dimension (LDB,NRHS) */
/* On entry, the right hand side matrix B. */
/* On exit, the solution matrix X. */
/* LDB (input) INTEGER */
/* The leading dimension of the array B. LDB >= max(1,N). */
/* INFO (output) INTEGER */
/* = 0: successful exit */
/* < 0: if INFO = -i, the i-th argument had an illegal value */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Test the input parameters. */
/* Parameter adjustments */
ab_dim1 = *ldab;
ab_offset = 1 + ab_dim1;
ab -= ab_offset;
--ipiv;
b_dim1 = *ldb;
b_offset = 1 + b_dim1;
b -= b_offset;
/* Function Body */
*info = 0;
notran = lsame_(trans, "N");
if (! notran && ! lsame_(trans, "T") && ! lsame_(
trans, "C")) {
*info = -1;
} else if (*n < 0) {
*info = -2;
} else if (*kl < 0) {
*info = -3;
} else if (*ku < 0) {
*info = -4;
} else if (*nrhs < 0) {
*info = -5;
} else if (*ldab < (*kl << 1) + *ku + 1) {
*info = -7;
} else if (*ldb < max(1,*n)) {
*info = -10;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("ZGBTRS", &i__1);
return 0;
}
/* Quick return if possible */
if (*n == 0 || *nrhs == 0) {
return 0;
}
kd = *ku + *kl + 1;
lnoti = *kl > 0;
if (notran) {
/* Solve A*X = B. */
/* Solve L*X = B, overwriting B with X. */
/* L is represented as a product of permutations and unit lower */
/* triangular matrices L = P(1) * L(1) * ... * P(n-1) * L(n-1), */
/* where each transformation L(i) is a rank-one modification of */
/* the identity matrix. */
if (lnoti) {
i__1 = *n - 1;
for (j = 1; j <= i__1; ++j) {
/* Computing MIN */
i__2 = *kl, i__3 = *n - j;
lm = min(i__2,i__3);
l = ipiv[j];
if (l != j) {
zswap_(nrhs, &b[l + b_dim1], ldb, &b[j + b_dim1], ldb);
}
z__1.r = -1., z__1.i = -0.;
zgeru_(&lm, nrhs, &z__1, &ab[kd + 1 + j * ab_dim1], &c__1, &b[
j + b_dim1], ldb, &b[j + 1 + b_dim1], ldb);
/* L10: */
}
}
i__1 = *nrhs;
for (i__ = 1; i__ <= i__1; ++i__) {
/* Solve U*X = B, overwriting B with X. */
i__2 = *kl + *ku;
ztbsv_("Upper", "No transpose", "Non-unit", n, &i__2, &ab[
ab_offset], ldab, &b[i__ * b_dim1 + 1], &c__1);
/* L20: */
}
} else if (lsame_(trans, "T")) {
/* Solve A**T * X = B. */
i__1 = *nrhs;
for (i__ = 1; i__ <= i__1; ++i__) {
/* Solve U**T * X = B, overwriting B with X. */
i__2 = *kl + *ku;
ztbsv_("Upper", "Transpose", "Non-unit", n, &i__2, &ab[ab_offset],
ldab, &b[i__ * b_dim1 + 1], &c__1);
/* L30: */
}
/* Solve L**T * X = B, overwriting B with X. */
if (lnoti) {
for (j = *n - 1; j >= 1; --j) {
/* Computing MIN */
i__1 = *kl, i__2 = *n - j;
lm = min(i__1,i__2);
z__1.r = -1., z__1.i = -0.;
zgemv_("Transpose", &lm, nrhs, &z__1, &b[j + 1 + b_dim1], ldb,
&ab[kd + 1 + j * ab_dim1], &c__1, &c_b1, &b[j +
b_dim1], ldb);
l = ipiv[j];
if (l != j) {
zswap_(nrhs, &b[l + b_dim1], ldb, &b[j + b_dim1], ldb);
}
/* L40: */
}
}
} else {
/* Solve A**H * X = B. */
i__1 = *nrhs;
for (i__ = 1; i__ <= i__1; ++i__) {
/* Solve U**H * X = B, overwriting B with X. */
i__2 = *kl + *ku;
ztbsv_("Upper", "Conjugate transpose", "Non-unit", n, &i__2, &ab[
ab_offset], ldab, &b[i__ * b_dim1 + 1], &c__1);
/* L50: */
}
/* Solve L**H * X = B, overwriting B with X. */
if (lnoti) {
for (j = *n - 1; j >= 1; --j) {
/* Computing MIN */
i__1 = *kl, i__2 = *n - j;
lm = min(i__1,i__2);
zlacgv_(nrhs, &b[j + b_dim1], ldb);
z__1.r = -1., z__1.i = -0.;
zgemv_("Conjugate transpose", &lm, nrhs, &z__1, &b[j + 1 +
b_dim1], ldb, &ab[kd + 1 + j * ab_dim1], &c__1, &c_b1,
&b[j + b_dim1], ldb);
zlacgv_(nrhs, &b[j + b_dim1], ldb);
l = ipiv[j];
if (l != j) {
zswap_(nrhs, &b[l + b_dim1], ldb, &b[j + b_dim1], ldb);
}
/* L60: */
}
}
}
return 0;
/* End of ZGBTRS */
} /* zgbtrs_ */
/* Subroutine */ int zchktb_(logical *dotype, integer *nn, integer *nval,
integer *nns, integer *nsval, doublereal *thresh, logical *tsterr,
integer *nmax, doublecomplex *ab, doublecomplex *ainv, doublecomplex *
b, doublecomplex *x, doublecomplex *xact, doublecomplex *work,
doublereal *rwork, integer *nout)
{
/* Initialized data */
static integer iseedy[4] = { 1988,1989,1990,1991 };
static char uplos[1*2] = "U" "L";
static char transs[1*3] = "N" "T" "C";
/* Format strings */
static char fmt_9999[] = "(\002 UPLO='\002,a1,\002', TRANS='\002,a1,\002"
"', DIAG='\002,a1,\002', N=\002,i5,\002, K"
"D=\002,i5,\002, NRHS=\002,i5,\002, type \002,i2,\002, test(\002,"
"i2,\002)=\002,g12.5)";
static char fmt_9998[] = "(1x,a6,\002( '\002,a1,\002', '\002,a1,\002', "
"'\002,a1,\002',\002,i5,\002,\002,i5,\002, ... ), type \002,i2"
",\002, test(\002,i2,\002)=\002,g12.5)";
static char fmt_9997[] = "(1x,a6,\002( '\002,a1,\002', '\002,a1,\002', "
"'\002,a1,\002', '\002,a1,\002',\002,i5,\002,\002,i5,\002, ... )"
", type \002,i2,\002, test(\002,i1,\002)=\002,g12.5)";
/* System generated locals */
address a__1[3], a__2[4];
integer i__1, i__2, i__3, i__4, i__5, i__6[3], i__7[4];
char ch__1[3], ch__2[4];
/* Builtin functions
Subroutine */ int s_copy(char *, char *, ftnlen, ftnlen), s_cat(char *,
char **, integer *, integer *, ftnlen);
integer s_wsfe(cilist *), do_fio(integer *, char *, ftnlen), e_wsfe(void);
/* Local variables */
static integer ldab;
static char diag[1];
static integer imat, info;
static char path[3];
static integer irhs, nrhs;
static char norm[1], uplo[1];
static integer nrun, i__, j, k;
extern /* Subroutine */ int alahd_(integer *, char *);
static integer idiag, n;
static doublereal scale;
static integer nfail, iseed[4];
extern logical lsame_(char *, char *);
static doublereal rcond;
static integer nimat;
static doublereal anorm;
static integer itran;
extern /* Subroutine */ int zget04_(integer *, integer *, doublecomplex *,
integer *, doublecomplex *, integer *, doublereal *, doublereal *
), ztbt02_(char *, char *, char *, integer *, integer *, integer *
, doublecomplex *, integer *, doublecomplex *, integer *,
doublecomplex *, integer *, doublecomplex *, doublereal *,
doublereal *), ztbt03_(char *, char *,
char *, integer *, integer *, integer *, doublecomplex *, integer
*, doublereal *, doublereal *, doublereal *, doublecomplex *,
integer *, doublecomplex *, integer *, doublecomplex *,
doublereal *);
static char trans[1];
static integer iuplo, nerrs;
extern /* Subroutine */ int ztbt05_(char *, char *, char *, integer *,
integer *, integer *, doublecomplex *, integer *, doublecomplex *,
integer *, doublecomplex *, integer *, doublecomplex *, integer *
, doublereal *, doublereal *, doublereal *), ztbt06_(doublereal *, doublereal *, char *, char *,
integer *, integer *, doublecomplex *, integer *, doublereal *,
doublereal *), zcopy_(integer *, doublecomplex *,
integer *, doublecomplex *, integer *), ztbsv_(char *, char *,
char *, integer *, integer *, doublecomplex *, integer *,
doublecomplex *, integer *);
static char xtype[1];
static integer nimat2, kd, ik, in, nk;
extern /* Subroutine */ int alaerh_(char *, char *, integer *, integer *,
char *, integer *, integer *, integer *, integer *, integer *,
integer *, integer *, integer *, integer *);
static doublereal rcondc, rcondi;
extern /* Subroutine */ int alasum_(char *, integer *, integer *, integer
*, integer *);
static doublereal rcondo, ainvnm;
extern doublereal zlantb_(char *, char *, char *, integer *, integer *,
doublecomplex *, integer *, doublereal *);
extern /* Subroutine */ int zlatbs_(char *, char *, char *, char *,
integer *, integer *, doublecomplex *, integer *, doublecomplex *,
doublereal *, doublereal *, integer *), zlattb_(integer *, char *, char *, char *, integer *,
integer *, integer *, doublecomplex *, integer *, doublecomplex *,
doublecomplex *, doublereal *, integer *)
, ztbcon_(char *, char *, char *, integer *, integer *,
doublecomplex *, integer *, doublereal *, doublecomplex *,
doublereal *, integer *), zlacpy_(char *,
integer *, integer *, doublecomplex *, integer *, doublecomplex *,
integer *), zlarhs_(char *, char *, char *, char *,
integer *, integer *, integer *, integer *, integer *,
doublecomplex *, integer *, doublecomplex *, integer *,
doublecomplex *, integer *, integer *, integer *), zlaset_(char *, integer *, integer *,
doublecomplex *, doublecomplex *, doublecomplex *, integer *);
extern doublereal zlantr_(char *, char *, char *, integer *, integer *,
doublecomplex *, integer *, doublereal *);
extern /* Subroutine */ int ztbrfs_(char *, char *, char *, integer *,
integer *, integer *, doublecomplex *, integer *, doublecomplex *,
integer *, doublecomplex *, integer *, doublereal *, doublereal *
, doublecomplex *, doublereal *, integer *);
static doublereal result[8];
extern /* Subroutine */ int zerrtr_(char *, integer *), ztbtrs_(
char *, char *, char *, integer *, integer *, integer *,
doublecomplex *, integer *, doublecomplex *, integer *, integer *);
static integer lda;
/* Fortran I/O blocks */
static cilist io___39 = { 0, 0, 0, fmt_9999, 0 };
static cilist io___41 = { 0, 0, 0, fmt_9998, 0 };
static cilist io___43 = { 0, 0, 0, fmt_9997, 0 };
static cilist io___44 = { 0, 0, 0, fmt_9997, 0 };
/* -- LAPACK test routine (version 3.0) --
Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
Courant Institute, Argonne National Lab, and Rice University
December 3, 1999
Purpose
=======
ZCHKTB tests ZTBTRS, -RFS, and -CON, and ZLATBS.
Arguments
=========
DOTYPE (input) LOGICAL array, dimension (NTYPES)
The matrix types to be used for testing. Matrices of type j
(for 1 <= j <= NTYPES) are used for testing if DOTYPE(j) =
.TRUE.; if DOTYPE(j) = .FALSE., then type j is not used.
NN (input) INTEGER
The number of values of N contained in the vector NVAL.
NVAL (input) INTEGER array, dimension (NN)
The values of the matrix column dimension N.
NNS (input) INTEGER
The number of values of NRHS contained in the vector NSVAL.
NSVAL (input) INTEGER array, dimension (NNS)
The values of the number of right hand sides NRHS.
THRESH (input) DOUBLE PRECISION
The threshold value for the test ratios. A result is
included in the output file if RESULT >= THRESH. To have
every test ratio printed, use THRESH = 0.
TSTERR (input) LOGICAL
Flag that indicates whether error exits are to be tested.
NMAX (input) INTEGER
The leading dimension of the work arrays.
NMAX >= the maximum value of N in NVAL.
AB (workspace) COMPLEX*16 array, dimension (NMAX*NMAX)
AINV (workspace) COMPLEX*16 array, dimension (NMAX*NMAX)
B (workspace) COMPLEX*16 array, dimension (NMAX*NSMAX)
where NSMAX is the largest entry in NSVAL.
X (workspace) COMPLEX*16 array, dimension (NMAX*NSMAX)
XACT (workspace) COMPLEX*16 array, dimension (NMAX*NSMAX)
WORK (workspace) COMPLEX*16 array, dimension
(NMAX*max(3,NSMAX))
RWORK (workspace) DOUBLE PRECISION array, dimension
(max(NMAX,2*NSMAX))
NOUT (input) INTEGER
The unit number for output.
=====================================================================
Parameter adjustments */
--rwork;
--work;
--xact;
--x;
--b;
--ainv;
--ab;
--nsval;
--nval;
--dotype;
/* Function Body
Initialize constants and the random number seed. */
s_copy(path, "Zomplex precision", (ftnlen)1, (ftnlen)17);
s_copy(path + 1, "TB", (ftnlen)2, (ftnlen)2);
nrun = 0;
nfail = 0;
nerrs = 0;
for (i__ = 1; i__ <= 4; ++i__) {
iseed[i__ - 1] = iseedy[i__ - 1];
/* L10: */
}
/* Test the error exits */
if (*tsterr) {
zerrtr_(path, nout);
}
infoc_1.infot = 0;
i__1 = *nn;
for (in = 1; in <= i__1; ++in) {
/* Do for each value of N in NVAL */
n = nval[in];
lda = max(1,n);
*(unsigned char *)xtype = 'N';
nimat = 9;
nimat2 = 17;
if (n <= 0) {
nimat = 1;
nimat2 = 10;
}
/* Computing MIN */
i__2 = n + 1;
nk = min(i__2,4);
i__2 = nk;
for (ik = 1; ik <= i__2; ++ik) {
/* Do for KD = 0, N, (3N-1)/4, and (N+1)/4. This order makes
it easier to skip redundant values for small values of N. */
if (ik == 1) {
kd = 0;
} else if (ik == 2) {
kd = max(n,0);
} else if (ik == 3) {
kd = (n * 3 - 1) / 4;
} else if (ik == 4) {
kd = (n + 1) / 4;
}
ldab = kd + 1;
i__3 = nimat;
for (imat = 1; imat <= i__3; ++imat) {
/* Do the tests only if DOTYPE( IMAT ) is true. */
if (! dotype[imat]) {
goto L90;
}
for (iuplo = 1; iuplo <= 2; ++iuplo) {
/* Do first for UPLO = 'U', then for UPLO = 'L' */
*(unsigned char *)uplo = *(unsigned char *)&uplos[iuplo -
1];
/* Call ZLATTB to generate a triangular test matrix. */
s_copy(srnamc_1.srnamt, "ZLATTB", (ftnlen)6, (ftnlen)6);
zlattb_(&imat, uplo, "No transpose", diag, iseed, &n, &kd,
&ab[1], &ldab, &x[1], &work[1], &rwork[1], &info);
/* Set IDIAG = 1 for non-unit matrices, 2 for unit. */
if (lsame_(diag, "N")) {
idiag = 1;
} else {
idiag = 2;
}
/* Form the inverse of A so we can get a good estimate
of RCONDC = 1/(norm(A) * norm(inv(A))). */
zlaset_("Full", &n, &n, &c_b14, &c_b15, &ainv[1], &lda);
if (lsame_(uplo, "U")) {
i__4 = n;
for (j = 1; j <= i__4; ++j) {
ztbsv_(uplo, "No transpose", diag, &j, &kd, &ab[1]
, &ldab, &ainv[(j - 1) * lda + 1], &c__1);
/* L20: */
}
} else {
i__4 = n;
for (j = 1; j <= i__4; ++j) {
i__5 = n - j + 1;
ztbsv_(uplo, "No transpose", diag, &i__5, &kd, &
ab[(j - 1) * ldab + 1], &ldab, &ainv[(j -
1) * lda + j], &c__1);
/* L30: */
}
}
/* Compute the 1-norm condition number of A. */
anorm = zlantb_("1", uplo, diag, &n, &kd, &ab[1], &ldab, &
rwork[1]);
ainvnm = zlantr_("1", uplo, diag, &n, &n, &ainv[1], &lda,
&rwork[1]);
if (anorm <= 0. || ainvnm <= 0.) {
rcondo = 1.;
} else {
rcondo = 1. / anorm / ainvnm;
}
/* Compute the infinity-norm condition number of A. */
anorm = zlantb_("I", uplo, diag, &n, &kd, &ab[1], &ldab, &
rwork[1]);
ainvnm = zlantr_("I", uplo, diag, &n, &n, &ainv[1], &lda,
&rwork[1]);
if (anorm <= 0. || ainvnm <= 0.) {
rcondi = 1.;
} else {
rcondi = 1. / anorm / ainvnm;
}
i__4 = *nns;
for (irhs = 1; irhs <= i__4; ++irhs) {
nrhs = nsval[irhs];
*(unsigned char *)xtype = 'N';
for (itran = 1; itran <= 3; ++itran) {
/* Do for op(A) = A, A**T, or A**H. */
*(unsigned char *)trans = *(unsigned char *)&
transs[itran - 1];
if (itran == 1) {
*(unsigned char *)norm = 'O';
rcondc = rcondo;
} else {
*(unsigned char *)norm = 'I';
rcondc = rcondi;
}
/* + TEST 1
Solve and compute residual for op(A)*x = b. */
s_copy(srnamc_1.srnamt, "ZLARHS", (ftnlen)6, (
ftnlen)6);
zlarhs_(path, xtype, uplo, trans, &n, &n, &kd, &
idiag, &nrhs, &ab[1], &ldab, &xact[1], &
lda, &b[1], &lda, iseed, &info);
*(unsigned char *)xtype = 'C';
zlacpy_("Full", &n, &nrhs, &b[1], &lda, &x[1], &
lda);
s_copy(srnamc_1.srnamt, "ZTBTRS", (ftnlen)6, (
ftnlen)6);
ztbtrs_(uplo, trans, diag, &n, &kd, &nrhs, &ab[1],
&ldab, &x[1], &lda, &info);
/* Check error code from ZTBTRS. */
if (info != 0) {
/* Writing concatenation */
i__6[0] = 1, a__1[0] = uplo;
i__6[1] = 1, a__1[1] = trans;
i__6[2] = 1, a__1[2] = diag;
s_cat(ch__1, a__1, i__6, &c__3, (ftnlen)3);
alaerh_(path, "ZTBTRS", &info, &c__0, ch__1, &
n, &n, &kd, &kd, &nrhs, &imat, &nfail,
&nerrs, nout);
}
ztbt02_(uplo, trans, diag, &n, &kd, &nrhs, &ab[1],
&ldab, &x[1], &lda, &b[1], &lda, &work[1]
, &rwork[1], result);
/* + TEST 2
Check solution from generated exact solution. */
zget04_(&n, &nrhs, &x[1], &lda, &xact[1], &lda, &
rcondc, &result[1]);
/* + TESTS 3, 4, and 5
Use iterative refinement to improve the solution
and compute error bounds. */
s_copy(srnamc_1.srnamt, "ZTBRFS", (ftnlen)6, (
ftnlen)6);
ztbrfs_(uplo, trans, diag, &n, &kd, &nrhs, &ab[1],
&ldab, &b[1], &lda, &x[1], &lda, &rwork[
1], &rwork[nrhs + 1], &work[1], &rwork[(
nrhs << 1) + 1], &info);
/* Check error code from ZTBRFS. */
if (info != 0) {
/* Writing concatenation */
i__6[0] = 1, a__1[0] = uplo;
i__6[1] = 1, a__1[1] = trans;
i__6[2] = 1, a__1[2] = diag;
s_cat(ch__1, a__1, i__6, &c__3, (ftnlen)3);
alaerh_(path, "ZTBRFS", &info, &c__0, ch__1, &
n, &n, &kd, &kd, &nrhs, &imat, &nfail,
&nerrs, nout);
}
zget04_(&n, &nrhs, &x[1], &lda, &xact[1], &lda, &
rcondc, &result[2]);
ztbt05_(uplo, trans, diag, &n, &kd, &nrhs, &ab[1],
&ldab, &b[1], &lda, &x[1], &lda, &xact[1]
, &lda, &rwork[1], &rwork[nrhs + 1], &
result[3]);
/* Print information about the tests that did not
pass the threshold. */
for (k = 1; k <= 5; ++k) {
if (result[k - 1] >= *thresh) {
if (nfail == 0 && nerrs == 0) {
alahd_(nout, path);
}
io___39.ciunit = *nout;
s_wsfe(&io___39);
do_fio(&c__1, uplo, (ftnlen)1);
do_fio(&c__1, trans, (ftnlen)1);
do_fio(&c__1, diag, (ftnlen)1);
do_fio(&c__1, (char *)&n, (ftnlen)sizeof(
integer));
do_fio(&c__1, (char *)&kd, (ftnlen)sizeof(
integer));
do_fio(&c__1, (char *)&nrhs, (ftnlen)
sizeof(integer));
do_fio(&c__1, (char *)&imat, (ftnlen)
sizeof(integer));
do_fio(&c__1, (char *)&k, (ftnlen)sizeof(
integer));
do_fio(&c__1, (char *)&result[k - 1], (
ftnlen)sizeof(doublereal));
e_wsfe();
++nfail;
}
/* L40: */
}
nrun += 5;
/* L50: */
}
/* L60: */
}
/* + TEST 6
Get an estimate of RCOND = 1/CNDNUM. */
for (itran = 1; itran <= 2; ++itran) {
if (itran == 1) {
*(unsigned char *)norm = 'O';
rcondc = rcondo;
} else {
*(unsigned char *)norm = 'I';
rcondc = rcondi;
}
s_copy(srnamc_1.srnamt, "ZTBCON", (ftnlen)6, (ftnlen)
6);
ztbcon_(norm, uplo, diag, &n, &kd, &ab[1], &ldab, &
rcond, &work[1], &rwork[1], &info);
/* Check error code from ZTBCON. */
if (info != 0) {
/* Writing concatenation */
i__6[0] = 1, a__1[0] = norm;
i__6[1] = 1, a__1[1] = uplo;
i__6[2] = 1, a__1[2] = diag;
s_cat(ch__1, a__1, i__6, &c__3, (ftnlen)3);
alaerh_(path, "ZTBCON", &info, &c__0, ch__1, &n, &
n, &kd, &kd, &c_n1, &imat, &nfail, &nerrs,
nout);
}
ztbt06_(&rcond, &rcondc, uplo, diag, &n, &kd, &ab[1],
&ldab, &rwork[1], &result[5]);
/* Print the test ratio if it is .GE. THRESH. */
if (result[5] >= *thresh) {
if (nfail == 0 && nerrs == 0) {
alahd_(nout, path);
}
io___41.ciunit = *nout;
s_wsfe(&io___41);
do_fio(&c__1, "ZTBCON", (ftnlen)6);
do_fio(&c__1, norm, (ftnlen)1);
do_fio(&c__1, uplo, (ftnlen)1);
do_fio(&c__1, diag, (ftnlen)1);
do_fio(&c__1, (char *)&n, (ftnlen)sizeof(integer))
;
do_fio(&c__1, (char *)&kd, (ftnlen)sizeof(integer)
);
do_fio(&c__1, (char *)&imat, (ftnlen)sizeof(
integer));
do_fio(&c__1, (char *)&c__6, (ftnlen)sizeof(
integer));
do_fio(&c__1, (char *)&result[5], (ftnlen)sizeof(
doublereal));
e_wsfe();
++nfail;
}
++nrun;
/* L70: */
}
/* L80: */
}
L90:
;
}
/* Use pathological test matrices to test ZLATBS. */
i__3 = nimat2;
for (imat = 10; imat <= i__3; ++imat) {
/* Do the tests only if DOTYPE( IMAT ) is true. */
if (! dotype[imat]) {
goto L120;
}
for (iuplo = 1; iuplo <= 2; ++iuplo) {
/* Do first for UPLO = 'U', then for UPLO = 'L' */
*(unsigned char *)uplo = *(unsigned char *)&uplos[iuplo -
1];
for (itran = 1; itran <= 3; ++itran) {
/* Do for op(A) = A, A**T, and A**H. */
*(unsigned char *)trans = *(unsigned char *)&transs[
itran - 1];
/* Call ZLATTB to generate a triangular test matrix. */
s_copy(srnamc_1.srnamt, "ZLATTB", (ftnlen)6, (ftnlen)
6);
zlattb_(&imat, uplo, trans, diag, iseed, &n, &kd, &ab[
1], &ldab, &x[1], &work[1], &rwork[1], &info);
/* + TEST 7
Solve the system op(A)*x = b */
s_copy(srnamc_1.srnamt, "ZLATBS", (ftnlen)6, (ftnlen)
6);
zcopy_(&n, &x[1], &c__1, &b[1], &c__1);
zlatbs_(uplo, trans, diag, "N", &n, &kd, &ab[1], &
ldab, &b[1], &scale, &rwork[1], &info);
/* Check error code from ZLATBS. */
if (info != 0) {
/* Writing concatenation */
i__7[0] = 1, a__2[0] = uplo;
i__7[1] = 1, a__2[1] = trans;
i__7[2] = 1, a__2[2] = diag;
i__7[3] = 1, a__2[3] = "N";
s_cat(ch__2, a__2, i__7, &c__4, (ftnlen)4);
alaerh_(path, "ZLATBS", &info, &c__0, ch__2, &n, &
n, &kd, &kd, &c_n1, &imat, &nfail, &nerrs,
nout);
}
ztbt03_(uplo, trans, diag, &n, &kd, &c__1, &ab[1], &
ldab, &scale, &rwork[1], &c_b90, &b[1], &lda,
&x[1], &lda, &work[1], &result[6]);
/* + TEST 8
Solve op(A)*x = b again with NORMIN = 'Y'. */
zcopy_(&n, &x[1], &c__1, &b[1], &c__1);
zlatbs_(uplo, trans, diag, "Y", &n, &kd, &ab[1], &
ldab, &b[1], &scale, &rwork[1], &info);
/* Check error code from ZLATBS. */
if (info != 0) {
/* Writing concatenation */
i__7[0] = 1, a__2[0] = uplo;
i__7[1] = 1, a__2[1] = trans;
i__7[2] = 1, a__2[2] = diag;
i__7[3] = 1, a__2[3] = "Y";
s_cat(ch__2, a__2, i__7, &c__4, (ftnlen)4);
alaerh_(path, "ZLATBS", &info, &c__0, ch__2, &n, &
n, &kd, &kd, &c_n1, &imat, &nfail, &nerrs,
nout);
}
ztbt03_(uplo, trans, diag, &n, &kd, &c__1, &ab[1], &
ldab, &scale, &rwork[1], &c_b90, &b[1], &lda,
&x[1], &lda, &work[1], &result[7]);
/* Print information about the tests that did not pass
the threshold. */
if (result[6] >= *thresh) {
if (nfail == 0 && nerrs == 0) {
alahd_(nout, path);
}
io___43.ciunit = *nout;
s_wsfe(&io___43);
do_fio(&c__1, "ZLATBS", (ftnlen)6);
do_fio(&c__1, uplo, (ftnlen)1);
do_fio(&c__1, trans, (ftnlen)1);
do_fio(&c__1, diag, (ftnlen)1);
do_fio(&c__1, "N", (ftnlen)1);
do_fio(&c__1, (char *)&n, (ftnlen)sizeof(integer))
;
do_fio(&c__1, (char *)&kd, (ftnlen)sizeof(integer)
);
do_fio(&c__1, (char *)&imat, (ftnlen)sizeof(
integer));
do_fio(&c__1, (char *)&c__7, (ftnlen)sizeof(
integer));
do_fio(&c__1, (char *)&result[6], (ftnlen)sizeof(
doublereal));
e_wsfe();
++nfail;
}
if (result[7] >= *thresh) {
if (nfail == 0 && nerrs == 0) {
alahd_(nout, path);
}
io___44.ciunit = *nout;
s_wsfe(&io___44);
do_fio(&c__1, "ZLATBS", (ftnlen)6);
do_fio(&c__1, uplo, (ftnlen)1);
do_fio(&c__1, trans, (ftnlen)1);
do_fio(&c__1, diag, (ftnlen)1);
do_fio(&c__1, "Y", (ftnlen)1);
do_fio(&c__1, (char *)&n, (ftnlen)sizeof(integer))
;
do_fio(&c__1, (char *)&kd, (ftnlen)sizeof(integer)
);
do_fio(&c__1, (char *)&imat, (ftnlen)sizeof(
integer));
do_fio(&c__1, (char *)&c__8, (ftnlen)sizeof(
integer));
do_fio(&c__1, (char *)&result[7], (ftnlen)sizeof(
doublereal));
e_wsfe();
++nfail;
}
nrun += 2;
/* L100: */
}
/* L110: */
}
L120:
;
}
/* L130: */
}
/* L140: */
}
/* Print a summary of the results. */
alasum_(path, nout, &nfail, &nrun, &nerrs);
return 0;
/* End of ZCHKTB */
} /* zchktb_ */
