/* Subroutine */ int cpbsvx_(char *fact, char *uplo, integer *n, integer *kd, integer *nrhs, complex *ab, integer *ldab, complex *afb, integer * ldafb, char *equed, real *s, complex *b, integer *ldb, complex *x, integer *ldx, real *rcond, real *ferr, real *berr, complex *work, real *rwork, integer *info) { /* System generated locals */ integer ab_dim1, ab_offset, afb_dim1, afb_offset, b_dim1, b_offset, x_dim1, x_offset, i__1, i__2, i__3, i__4, i__5; real r__1, r__2; complex q__1; /* Local variables */ integer i__, j, j1, j2; real amax, smin, smax; extern logical lsame_(char *, char *); real scond, anorm; extern /* Subroutine */ int ccopy_(integer *, complex *, integer *, complex *, integer *); logical equil, rcequ, upper; extern real clanhb_(char *, char *, integer *, integer *, complex *, integer *, real *); extern /* Subroutine */ int claqhb_(char *, integer *, integer *, complex *, integer *, real *, real *, real *, char *), cpbcon_(char *, integer *, integer *, complex *, integer *, real * , real *, complex *, real *, integer *); extern real slamch_(char *); logical nofact; extern /* Subroutine */ int clacpy_(char *, integer *, integer *, complex *, integer *, complex *, integer *), xerbla_(char *, integer *), cpbequ_(char *, integer *, integer *, complex *, integer *, real *, real *, real *, integer *), cpbrfs_( char *, integer *, integer *, integer *, complex *, integer *, complex *, integer *, complex *, integer *, complex *, integer *, real *, real *, complex *, real *, integer *); real bignum; extern /* Subroutine */ int cpbtrf_(char *, integer *, integer *, complex *, integer *, integer *); integer infequ; extern /* Subroutine */ int cpbtrs_(char *, integer *, integer *, integer *, complex *, integer *, complex *, integer *, integer *); real smlnum; /* -- LAPACK driver routine (version 3.4.1) -- */ /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */ /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */ /* April 2012 */ /* .. Scalar Arguments .. */ /* .. */ /* .. Array Arguments .. */ /* .. */ /* ===================================================================== */ /* .. Parameters .. */ /* .. */ /* .. Local Scalars .. */ /* .. */ /* .. External Functions .. */ /* .. */ /* .. External Subroutines .. */ /* .. */ /* .. Intrinsic Functions .. */ /* .. */ /* .. Executable Statements .. */ /* Parameter adjustments */ ab_dim1 = *ldab; ab_offset = 1 + ab_dim1; ab -= ab_offset; afb_dim1 = *ldafb; afb_offset = 1 + afb_dim1; afb -= afb_offset; --s; 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; nofact = lsame_(fact, "N"); equil = lsame_(fact, "E"); upper = lsame_(uplo, "U"); if (nofact || equil) { *(unsigned char *)equed = 'N'; rcequ = FALSE_; } else { rcequ = lsame_(equed, "Y"); smlnum = slamch_("Safe minimum"); bignum = 1.f / smlnum; } /* Test the input parameters. */ if (! nofact && ! equil && ! lsame_(fact, "F")) { *info = -1; } else if (! upper && ! lsame_(uplo, "L")) { *info = -2; } else if (*n < 0) { *info = -3; } else if (*kd < 0) { *info = -4; } else if (*nrhs < 0) { *info = -5; } else if (*ldab < *kd + 1) { *info = -7; } else if (*ldafb < *kd + 1) { *info = -9; } else if (lsame_(fact, "F") && ! (rcequ || lsame_( equed, "N"))) { *info = -10; } else { if (rcequ) { smin = bignum; smax = 0.f; i__1 = *n; for (j = 1; j <= i__1; ++j) { /* Computing MIN */ r__1 = smin; r__2 = s[j]; // , expr subst smin = min(r__1,r__2); /* Computing MAX */ r__1 = smax; r__2 = s[j]; // , expr subst smax = max(r__1,r__2); /* L10: */ } if (smin <= 0.f) { *info = -11; } else if (*n > 0) { scond = max(smin,smlnum) / min(smax,bignum); } else { scond = 1.f; } } if (*info == 0) { if (*ldb < max(1,*n)) { *info = -13; } else if (*ldx < max(1,*n)) { *info = -15; } } } if (*info != 0) { i__1 = -(*info); xerbla_("CPBSVX", &i__1); return 0; } if (equil) { /* Compute row and column scalings to equilibrate the matrix A. */ cpbequ_(uplo, n, kd, &ab[ab_offset], ldab, &s[1], &scond, &amax, & infequ); if (infequ == 0) { /* Equilibrate the matrix. */ claqhb_(uplo, n, kd, &ab[ab_offset], ldab, &s[1], &scond, &amax, equed); rcequ = lsame_(equed, "Y"); } } /* Scale the right-hand side. */ if (rcequ) { i__1 = *nrhs; for (j = 1; j <= i__1; ++j) { i__2 = *n; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * b_dim1; i__4 = i__; i__5 = i__ + j * b_dim1; q__1.r = s[i__4] * b[i__5].r; q__1.i = s[i__4] * b[i__5].i; // , expr subst b[i__3].r = q__1.r; b[i__3].i = q__1.i; // , expr subst /* L20: */ } /* L30: */ } } if (nofact || equil) { /* Compute the Cholesky factorization A = U**H *U or A = L*L**H. */ if (upper) { i__1 = *n; for (j = 1; j <= i__1; ++j) { /* Computing MAX */ i__2 = j - *kd; j1 = max(i__2,1); i__2 = j - j1 + 1; ccopy_(&i__2, &ab[*kd + 1 - j + j1 + j * ab_dim1], &c__1, & afb[*kd + 1 - j + j1 + j * afb_dim1], &c__1); /* L40: */ } } else { i__1 = *n; for (j = 1; j <= i__1; ++j) { /* Computing MIN */ i__2 = j + *kd; j2 = min(i__2,*n); i__2 = j2 - j + 1; ccopy_(&i__2, &ab[j * ab_dim1 + 1], &c__1, &afb[j * afb_dim1 + 1], &c__1); /* L50: */ } } cpbtrf_(uplo, n, kd, &afb[afb_offset], ldafb, info); /* Return if INFO is non-zero. */ if (*info > 0) { *rcond = 0.f; return 0; } } /* Compute the norm of the matrix A. */ anorm = clanhb_("1", uplo, n, kd, &ab[ab_offset], ldab, &rwork[1]); /* Compute the reciprocal of the condition number of A. */ cpbcon_(uplo, n, kd, &afb[afb_offset], ldafb, &anorm, rcond, &work[1], & rwork[1], info); /* Compute the solution matrix X. */ clacpy_("Full", n, nrhs, &b[b_offset], ldb, &x[x_offset], ldx); cpbtrs_(uplo, n, kd, nrhs, &afb[afb_offset], ldafb, &x[x_offset], ldx, info); /* Use iterative refinement to improve the computed solution and */ /* compute error bounds and backward error estimates for it. */ cpbrfs_(uplo, n, kd, nrhs, &ab[ab_offset], ldab, &afb[afb_offset], ldafb, &b[b_offset], ldb, &x[x_offset], ldx, &ferr[1], &berr[1], &work[1] , &rwork[1], info); /* Transform the solution matrix X to a solution of the original */ /* system. */ if (rcequ) { i__1 = *nrhs; for (j = 1; j <= i__1; ++j) { i__2 = *n; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * x_dim1; i__4 = i__; i__5 = i__ + j * x_dim1; q__1.r = s[i__4] * x[i__5].r; q__1.i = s[i__4] * x[i__5].i; // , expr subst x[i__3].r = q__1.r; x[i__3].i = q__1.i; // , expr subst /* L60: */ } /* L70: */ } i__1 = *nrhs; for (j = 1; j <= i__1; ++j) { ferr[j] /= scond; /* L80: */ } } /* Set INFO = N+1 if the matrix is singular to working precision. */ if (*rcond < slamch_("Epsilon")) { *info = *n + 1; } return 0; /* End of CPBSVX */ }
/* Subroutine */ int cdrvpb_(logical *dotype, integer *nn, integer *nval, integer *nrhs, real *thresh, logical *tsterr, integer *nmax, complex * a, complex *afac, complex *asav, complex *b, complex *bsav, complex * x, complex *xact, real *s, complex *work, real *rwork, integer *nout) { /* Initialized data */ static integer iseedy[4] = { 1988,1989,1990,1991 }; static char facts[1*3] = "F" "N" "E"; static char equeds[1*2] = "N" "Y"; /* Format strings */ static char fmt_9999[] = "(1x,a6,\002, UPLO='\002,a1,\002', N =\002,i5" ",\002, KD =\002,i5,\002, type \002,i1,\002, test(\002,i1,\002)" "=\002,g12.5)"; static char fmt_9997[] = "(1x,a6,\002( '\002,a1,\002', '\002,a1,\002'," " \002,i5,\002, \002,i5,\002, ... ), EQUED='\002,a1,\002', type" " \002,i1,\002, test(\002,i1,\002)=\002,g12.5)"; static char fmt_9998[] = "(1x,a6,\002( '\002,a1,\002', '\002,a1,\002'," " \002,i5,\002, \002,i5,\002, ... ), type \002,i1,\002, test(\002" ",i1,\002)=\002,g12.5)"; /* System generated locals */ address a__1[2]; integer i__1, i__2, i__3, i__4, i__5, i__6, i__7[2]; char ch__1[2]; /* Builtin functions */ /* Subroutine */ int s_copy(char *, char *, ftnlen, ftnlen); integer s_wsfe(cilist *), do_fio(integer *, char *, ftnlen), e_wsfe(void); /* Subroutine */ int s_cat(char *, char **, integer *, integer *, ftnlen); /* Local variables */ integer i__, k, n, i1, i2, k1, kd, nb, in, kl, iw, ku, nt, lda, ikd, nkd, ldab; char fact[1]; integer ioff, mode, koff; real amax; char path[3]; integer imat, info; char dist[1], uplo[1], type__[1]; integer nrun, ifact; extern /* Subroutine */ int cget04_(integer *, integer *, complex *, integer *, complex *, integer *, real *, real *); integer nfail, iseed[4], nfact; extern /* Subroutine */ int cpbt01_(char *, integer *, integer *, complex *, integer *, complex *, integer *, real *, real *), cpbt02_(char *, integer *, integer *, integer *, complex *, integer *, complex *, integer *, complex *, integer *, real *, real *), cpbt05_(char *, integer *, integer *, integer *, complex *, integer *, complex *, integer *, complex *, integer *, complex *, integer *, real *, real *, real *); integer kdval[4]; extern logical lsame_(char *, char *); char equed[1]; integer nbmin; real rcond, roldc, scond; integer nimat; extern doublereal sget06_(real *, real *); real anorm; extern /* Subroutine */ int ccopy_(integer *, complex *, integer *, complex *, integer *), cpbsv_(char *, integer *, integer *, integer *, complex *, integer *, complex *, integer *, integer *); logical equil; extern /* Subroutine */ int cswap_(integer *, complex *, integer *, complex *, integer *); integer iuplo, izero, nerrs; logical zerot; char xtype[1]; extern /* Subroutine */ int clatb4_(char *, integer *, integer *, integer *, char *, integer *, integer *, real *, integer *, real *, char * ), aladhd_(integer *, char *); extern doublereal clanhb_(char *, char *, integer *, integer *, complex *, integer *, real *), clange_(char *, integer *, integer *, complex *, integer *, real *); extern /* Subroutine */ int claqhb_(char *, integer *, integer *, complex *, integer *, real *, real *, real *, char *), alaerh_(char *, char *, integer *, integer *, char *, integer *, integer *, integer *, integer *, integer *, integer *, integer *, integer *, integer *), claipd_(integer *, complex *, integer *, integer *); logical prefac; real rcondc; logical nofact; char packit[1]; integer iequed; extern /* Subroutine */ int clacpy_(char *, integer *, integer *, complex *, integer *, complex *, integer *), clarhs_(char *, char *, char *, char *, integer *, integer *, integer *, integer *, integer *, complex *, integer *, complex *, integer *, complex *, integer *, integer *, integer *), claset_(char *, integer *, integer *, complex *, complex *, complex *, integer *), cpbequ_(char *, integer *, integer *, complex *, integer *, real *, real *, real *, integer *), alasvm_(char *, integer *, integer *, integer *, integer *); real cndnum; extern /* Subroutine */ int clatms_(integer *, integer *, char *, integer *, char *, real *, integer *, real *, real *, integer *, integer * , char *, complex *, integer *, complex *, integer *), cpbtrf_(char *, integer *, integer *, complex *, integer *, integer *); real ainvnm; extern /* Subroutine */ int cpbtrs_(char *, integer *, integer *, integer *, complex *, integer *, complex *, integer *, integer *), xlaenv_(integer *, integer *), cpbsvx_(char *, char *, integer *, integer *, integer *, complex *, integer *, complex *, integer *, char *, real *, complex *, integer *, complex *, integer *, real *, real *, real *, complex *, real *, integer *), cerrvx_(char *, integer *); real result[6]; /* Fortran I/O blocks */ static cilist io___57 = { 0, 0, 0, fmt_9999, 0 }; static cilist io___60 = { 0, 0, 0, fmt_9997, 0 }; static cilist io___61 = { 0, 0, 0, fmt_9998, 0 }; /* -- LAPACK test routine (version 3.1) -- */ /* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ /* November 2006 */ /* .. Scalar Arguments .. */ /* .. */ /* .. Array Arguments .. */ /* .. */ /* Purpose */ /* ======= */ /* CDRVPB tests the driver routines CPBSV and -SVX. */ /* 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 dimension N. */ /* NRHS (input) INTEGER */ /* The number of right hand side vectors to be generated for */ /* each linear system. */ /* THRESH (input) REAL */ /* 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 maximum value permitted for N, used in dimensioning the */ /* work arrays. */ /* A (workspace) COMPLEX array, dimension (NMAX*NMAX) */ /* AFAC (workspace) COMPLEX array, dimension (NMAX*NMAX) */ /* ASAV (workspace) COMPLEX array, dimension (NMAX*NMAX) */ /* B (workspace) COMPLEX array, dimension (NMAX*NRHS) */ /* BSAV (workspace) COMPLEX array, dimension (NMAX*NRHS) */ /* X (workspace) COMPLEX array, dimension (NMAX*NRHS) */ /* XACT (workspace) COMPLEX array, dimension (NMAX*NRHS) */ /* S (workspace) REAL array, dimension (NMAX) */ /* WORK (workspace) COMPLEX array, dimension */ /* (NMAX*max(3,NRHS)) */ /* RWORK (workspace) REAL array, dimension (NMAX+2*NRHS) */ /* NOUT (input) INTEGER */ /* The unit number for output. */ /* ===================================================================== */ /* .. Parameters .. */ /* .. */ /* .. Local Scalars .. */ /* .. */ /* .. Local Arrays .. */ /* .. */ /* .. External Functions .. */ /* .. */ /* .. External Subroutines .. */ /* .. */ /* .. Intrinsic Functions .. */ /* .. */ /* .. Scalars in Common .. */ /* .. */ /* .. Common blocks .. */ /* .. */ /* .. Data statements .. */ /* Parameter adjustments */ --rwork; --work; --s; --xact; --x; --bsav; --b; --asav; --afac; --a; --nval; --dotype; /* Function Body */ /* .. */ /* .. Executable Statements .. */ /* Initialize constants and the random number seed. */ s_copy(path, "Complex precision", (ftnlen)1, (ftnlen)17); s_copy(path + 1, "PB", (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) { cerrvx_(path, nout); } infoc_1.infot = 0; kdval[0] = 0; /* Set the block size and minimum block size for testing. */ nb = 1; nbmin = 2; xlaenv_(&c__1, &nb); xlaenv_(&c__2, &nbmin); /* Do for each value of N in NVAL */ i__1 = *nn; for (in = 1; in <= i__1; ++in) { n = nval[in]; lda = max(n,1); *(unsigned char *)xtype = 'N'; /* Set limits on the number of loop iterations. */ /* Computing MAX */ i__2 = 1, i__3 = min(n,4); nkd = max(i__2,i__3); nimat = 8; if (n == 0) { nimat = 1; } kdval[1] = n + (n + 1) / 4; kdval[2] = (n * 3 - 1) / 4; kdval[3] = (n + 1) / 4; i__2 = nkd; for (ikd = 1; ikd <= i__2; ++ikd) { /* Do for KD = 0, (5*N+1)/4, (3N-1)/4, and (N+1)/4. This order */ /* makes it easier to skip redundant values for small values */ /* of N. */ kd = kdval[ikd - 1]; ldab = kd + 1; /* Do first for UPLO = 'U', then for UPLO = 'L' */ for (iuplo = 1; iuplo <= 2; ++iuplo) { koff = 1; if (iuplo == 1) { *(unsigned char *)uplo = 'U'; *(unsigned char *)packit = 'Q'; /* Computing MAX */ i__3 = 1, i__4 = kd + 2 - n; koff = max(i__3,i__4); } else { *(unsigned char *)uplo = 'L'; *(unsigned char *)packit = 'B'; } i__3 = nimat; for (imat = 1; imat <= i__3; ++imat) { /* Do the tests only if DOTYPE( IMAT ) is true. */ if (! dotype[imat]) { goto L80; } /* Skip types 2, 3, or 4 if the matrix size is too small. */ zerot = imat >= 2 && imat <= 4; if (zerot && n < imat - 1) { goto L80; } if (! zerot || ! dotype[1]) { /* Set up parameters with CLATB4 and generate a test */ /* matrix with CLATMS. */ clatb4_(path, &imat, &n, &n, type__, &kl, &ku, &anorm, &mode, &cndnum, dist); s_copy(srnamc_1.srnamt, "CLATMS", (ftnlen)6, (ftnlen) 6); clatms_(&n, &n, dist, iseed, type__, &rwork[1], &mode, &cndnum, &anorm, &kd, &kd, packit, &a[koff], &ldab, &work[1], &info); /* Check error code from CLATMS. */ if (info != 0) { alaerh_(path, "CLATMS", &info, &c__0, uplo, &n, & n, &c_n1, &c_n1, &c_n1, &imat, &nfail, & nerrs, nout); goto L80; } } else if (izero > 0) { /* Use the same matrix for types 3 and 4 as for type */ /* 2 by copying back the zeroed out column, */ iw = (lda << 1) + 1; if (iuplo == 1) { ioff = (izero - 1) * ldab + kd + 1; i__4 = izero - i1; ccopy_(&i__4, &work[iw], &c__1, &a[ioff - izero + i1], &c__1); iw = iw + izero - i1; i__4 = i2 - izero + 1; /* Computing MAX */ i__6 = ldab - 1; i__5 = max(i__6,1); ccopy_(&i__4, &work[iw], &c__1, &a[ioff], &i__5); } else { ioff = (i1 - 1) * ldab + 1; i__4 = izero - i1; /* Computing MAX */ i__6 = ldab - 1; i__5 = max(i__6,1); ccopy_(&i__4, &work[iw], &c__1, &a[ioff + izero - i1], &i__5); ioff = (izero - 1) * ldab + 1; iw = iw + izero - i1; i__4 = i2 - izero + 1; ccopy_(&i__4, &work[iw], &c__1, &a[ioff], &c__1); } } /* For types 2-4, zero one row and column of the matrix */ /* to test that INFO is returned correctly. */ izero = 0; if (zerot) { if (imat == 2) { izero = 1; } else if (imat == 3) { izero = n; } else { izero = n / 2 + 1; } /* Save the zeroed out row and column in WORK(*,3) */ iw = lda << 1; /* Computing MIN */ i__5 = (kd << 1) + 1; i__4 = min(i__5,n); for (i__ = 1; i__ <= i__4; ++i__) { i__5 = iw + i__; work[i__5].r = 0.f, work[i__5].i = 0.f; /* L20: */ } ++iw; /* Computing MAX */ i__4 = izero - kd; i1 = max(i__4,1); /* Computing MIN */ i__4 = izero + kd; i2 = min(i__4,n); if (iuplo == 1) { ioff = (izero - 1) * ldab + kd + 1; i__4 = izero - i1; cswap_(&i__4, &a[ioff - izero + i1], &c__1, &work[ iw], &c__1); iw = iw + izero - i1; i__4 = i2 - izero + 1; /* Computing MAX */ i__6 = ldab - 1; i__5 = max(i__6,1); cswap_(&i__4, &a[ioff], &i__5, &work[iw], &c__1); } else { ioff = (i1 - 1) * ldab + 1; i__4 = izero - i1; /* Computing MAX */ i__6 = ldab - 1; i__5 = max(i__6,1); cswap_(&i__4, &a[ioff + izero - i1], &i__5, &work[ iw], &c__1); ioff = (izero - 1) * ldab + 1; iw = iw + izero - i1; i__4 = i2 - izero + 1; cswap_(&i__4, &a[ioff], &c__1, &work[iw], &c__1); } } /* Set the imaginary part of the diagonals. */ if (iuplo == 1) { claipd_(&n, &a[kd + 1], &ldab, &c__0); } else { claipd_(&n, &a[1], &ldab, &c__0); } /* Save a copy of the matrix A in ASAV. */ i__4 = kd + 1; clacpy_("Full", &i__4, &n, &a[1], &ldab, &asav[1], &ldab); for (iequed = 1; iequed <= 2; ++iequed) { *(unsigned char *)equed = *(unsigned char *)&equeds[ iequed - 1]; if (iequed == 1) { nfact = 3; } else { nfact = 1; } i__4 = nfact; for (ifact = 1; ifact <= i__4; ++ifact) { *(unsigned char *)fact = *(unsigned char *)&facts[ ifact - 1]; prefac = lsame_(fact, "F"); nofact = lsame_(fact, "N"); equil = lsame_(fact, "E"); if (zerot) { if (prefac) { goto L60; } rcondc = 0.f; } else if (! lsame_(fact, "N")) { /* Compute the condition number for comparison */ /* with the value returned by CPBSVX (FACT = */ /* 'N' reuses the condition number from the */ /* previous iteration with FACT = 'F'). */ i__5 = kd + 1; clacpy_("Full", &i__5, &n, &asav[1], &ldab, & afac[1], &ldab); if (equil || iequed > 1) { /* Compute row and column scale factors to */ /* equilibrate the matrix A. */ cpbequ_(uplo, &n, &kd, &afac[1], &ldab, & s[1], &scond, &amax, &info); if (info == 0 && n > 0) { if (iequed > 1) { scond = 0.f; } /* Equilibrate the matrix. */ claqhb_(uplo, &n, &kd, &afac[1], & ldab, &s[1], &scond, &amax, equed); } } /* Save the condition number of the */ /* non-equilibrated system for use in CGET04. */ if (equil) { roldc = rcondc; } /* Compute the 1-norm of A. */ anorm = clanhb_("1", uplo, &n, &kd, &afac[1], &ldab, &rwork[1]); /* Factor the matrix A. */ cpbtrf_(uplo, &n, &kd, &afac[1], &ldab, &info); /* Form the inverse of A. */ claset_("Full", &n, &n, &c_b47, &c_b48, &a[1], &lda); s_copy(srnamc_1.srnamt, "CPBTRS", (ftnlen)6, ( ftnlen)6); cpbtrs_(uplo, &n, &kd, &n, &afac[1], &ldab, & a[1], &lda, &info); /* Compute the 1-norm condition number of A. */ ainvnm = clange_("1", &n, &n, &a[1], &lda, & rwork[1]); if (anorm <= 0.f || ainvnm <= 0.f) { rcondc = 1.f; } else { rcondc = 1.f / anorm / ainvnm; } } /* Restore the matrix A. */ i__5 = kd + 1; clacpy_("Full", &i__5, &n, &asav[1], &ldab, &a[1], &ldab); /* Form an exact solution and set the right hand */ /* side. */ s_copy(srnamc_1.srnamt, "CLARHS", (ftnlen)6, ( ftnlen)6); clarhs_(path, xtype, uplo, " ", &n, &n, &kd, &kd, nrhs, &a[1], &ldab, &xact[1], &lda, &b[1], &lda, iseed, &info); *(unsigned char *)xtype = 'C'; clacpy_("Full", &n, nrhs, &b[1], &lda, &bsav[1], & lda); if (nofact) { /* --- Test CPBSV --- */ /* Compute the L*L' or U'*U factorization of the */ /* matrix and solve the system. */ i__5 = kd + 1; clacpy_("Full", &i__5, &n, &a[1], &ldab, & afac[1], &ldab); clacpy_("Full", &n, nrhs, &b[1], &lda, &x[1], &lda); s_copy(srnamc_1.srnamt, "CPBSV ", (ftnlen)6, ( ftnlen)6); cpbsv_(uplo, &n, &kd, nrhs, &afac[1], &ldab, & x[1], &lda, &info); /* Check error code from CPBSV . */ if (info != izero) { alaerh_(path, "CPBSV ", &info, &izero, uplo, &n, &n, &kd, &kd, nrhs, & imat, &nfail, &nerrs, nout); goto L40; } else if (info != 0) { goto L40; } /* Reconstruct matrix from factors and compute */ /* residual. */ cpbt01_(uplo, &n, &kd, &a[1], &ldab, &afac[1], &ldab, &rwork[1], result); /* Compute residual of the computed solution. */ clacpy_("Full", &n, nrhs, &b[1], &lda, &work[ 1], &lda); cpbt02_(uplo, &n, &kd, nrhs, &a[1], &ldab, &x[ 1], &lda, &work[1], &lda, &rwork[1], & result[1]); /* Check solution from generated exact solution. */ cget04_(&n, nrhs, &x[1], &lda, &xact[1], &lda, &rcondc, &result[2]); nt = 3; /* Print information about the tests that did */ /* not pass the threshold. */ i__5 = nt; for (k = 1; k <= i__5; ++k) { if (result[k - 1] >= *thresh) { if (nfail == 0 && nerrs == 0) { aladhd_(nout, path); } io___57.ciunit = *nout; s_wsfe(&io___57); do_fio(&c__1, "CPBSV ", (ftnlen)6); do_fio(&c__1, uplo, (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 *)&k, (ftnlen) sizeof(integer)); do_fio(&c__1, (char *)&result[k - 1], (ftnlen)sizeof(real)); e_wsfe(); ++nfail; } /* L30: */ } nrun += nt; L40: ; } /* --- Test CPBSVX --- */ if (! prefac) { i__5 = kd + 1; claset_("Full", &i__5, &n, &c_b47, &c_b47, & afac[1], &ldab); } claset_("Full", &n, nrhs, &c_b47, &c_b47, &x[1], & lda); if (iequed > 1 && n > 0) { /* Equilibrate the matrix if FACT='F' and */ /* EQUED='Y' */ claqhb_(uplo, &n, &kd, &a[1], &ldab, &s[1], & scond, &amax, equed); } /* Solve the system and compute the condition */ /* number and error bounds using CPBSVX. */ s_copy(srnamc_1.srnamt, "CPBSVX", (ftnlen)6, ( ftnlen)6); cpbsvx_(fact, uplo, &n, &kd, nrhs, &a[1], &ldab, & afac[1], &ldab, equed, &s[1], &b[1], &lda, &x[1], &lda, &rcond, &rwork[1], &rwork[* nrhs + 1], &work[1], &rwork[(*nrhs << 1) + 1], &info); /* Check the error code from CPBSVX. */ if (info != izero) { /* Writing concatenation */ i__7[0] = 1, a__1[0] = fact; i__7[1] = 1, a__1[1] = uplo; s_cat(ch__1, a__1, i__7, &c__2, (ftnlen)2); alaerh_(path, "CPBSVX", &info, &izero, ch__1, &n, &n, &kd, &kd, nrhs, &imat, &nfail, &nerrs, nout); goto L60; } if (info == 0) { if (! prefac) { /* Reconstruct matrix from factors and */ /* compute residual. */ cpbt01_(uplo, &n, &kd, &a[1], &ldab, & afac[1], &ldab, &rwork[(*nrhs << 1) + 1], result); k1 = 1; } else { k1 = 2; } /* Compute residual of the computed solution. */ clacpy_("Full", &n, nrhs, &bsav[1], &lda, & work[1], &lda); cpbt02_(uplo, &n, &kd, nrhs, &asav[1], &ldab, &x[1], &lda, &work[1], &lda, &rwork[(* nrhs << 1) + 1], &result[1]); /* Check solution from generated exact solution. */ if (nofact || prefac && lsame_(equed, "N")) { cget04_(&n, nrhs, &x[1], &lda, &xact[1], & lda, &rcondc, &result[2]); } else { cget04_(&n, nrhs, &x[1], &lda, &xact[1], & lda, &roldc, &result[2]); } /* Check the error bounds from iterative */ /* refinement. */ cpbt05_(uplo, &n, &kd, nrhs, &asav[1], &ldab, &b[1], &lda, &x[1], &lda, &xact[1], & lda, &rwork[1], &rwork[*nrhs + 1], & result[3]); } else { k1 = 6; } /* Compare RCOND from CPBSVX with the computed */ /* value in RCONDC. */ result[5] = sget06_(&rcond, &rcondc); /* Print information about the tests that did not */ /* pass the threshold. */ for (k = k1; k <= 6; ++k) { if (result[k - 1] >= *thresh) { if (nfail == 0 && nerrs == 0) { aladhd_(nout, path); } if (prefac) { io___60.ciunit = *nout; s_wsfe(&io___60); do_fio(&c__1, "CPBSVX", (ftnlen)6); do_fio(&c__1, fact, (ftnlen)1); do_fio(&c__1, uplo, (ftnlen)1); do_fio(&c__1, (char *)&n, (ftnlen) sizeof(integer)); do_fio(&c__1, (char *)&kd, (ftnlen) sizeof(integer)); do_fio(&c__1, equed, (ftnlen)1); 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(real)); e_wsfe(); } else { io___61.ciunit = *nout; s_wsfe(&io___61); do_fio(&c__1, "CPBSVX", (ftnlen)6); do_fio(&c__1, fact, (ftnlen)1); do_fio(&c__1, uplo, (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 *)&k, (ftnlen) sizeof(integer)); do_fio(&c__1, (char *)&result[k - 1], (ftnlen)sizeof(real)); e_wsfe(); } ++nfail; } /* L50: */ } nrun = nrun + 7 - k1; L60: ; } /* L70: */ } L80: ; } /* L90: */ } /* L100: */ } /* L110: */ } /* Print a summary of the results. */ alasvm_(path, nout, &nfail, &nrun, &nerrs); return 0; /* End of CDRVPB */ } /* cdrvpb_ */
int cpbsvx_(char *fact, char *uplo, int *n, int *kd, int *nrhs, complex *ab, int *ldab, complex *afb, int * ldafb, char *equed, float *s, complex *b, int *ldb, complex *x, int *ldx, float *rcond, float *ferr, float *berr, complex *work, float *rwork, int *info) { /* System generated locals */ int ab_dim1, ab_offset, afb_dim1, afb_offset, b_dim1, b_offset, x_dim1, x_offset, i__1, i__2, i__3, i__4, i__5; float r__1, r__2; complex q__1; /* Local variables */ int i__, j, j1, j2; float amax, smin, smax; extern int lsame_(char *, char *); float scond, anorm; extern int ccopy_(int *, complex *, int *, complex *, int *); int equil, rcequ, upper; extern double clanhb_(char *, char *, int *, int *, complex *, int *, float *); extern int claqhb_(char *, int *, int *, complex *, int *, float *, float *, float *, char *), cpbcon_(char *, int *, int *, complex *, int *, float * , float *, complex *, float *, int *); extern double slamch_(char *); int nofact; extern int clacpy_(char *, int *, int *, complex *, int *, complex *, int *), xerbla_(char *, int *), cpbequ_(char *, int *, int *, complex *, int *, float *, float *, float *, int *), cpbrfs_( char *, int *, int *, int *, complex *, int *, complex *, int *, complex *, int *, complex *, int *, float *, float *, complex *, float *, int *); float bignum; extern int cpbtrf_(char *, int *, int *, complex *, int *, int *); int infequ; extern int cpbtrs_(char *, int *, int *, int *, complex *, int *, complex *, int *, int *); float smlnum; /* -- LAPACK driver routine (version 3.2) -- */ /* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */ /* November 2006 */ /* .. Scalar Arguments .. */ /* .. */ /* .. Array Arguments .. */ /* .. */ /* Purpose */ /* ======= */ /* CPBSVX uses the Cholesky factorization A = U**H*U or A = L*L**H to */ /* compute the solution to a complex system of linear equations */ /* A * X = B, */ /* where A is an N-by-N Hermitian positive definite band matrix and X */ /* and B are N-by-NRHS matrices. */ /* Error bounds on the solution and a condition estimate are also */ /* provided. */ /* Description */ /* =========== */ /* The following steps are performed: */ /* 1. If FACT = 'E', float scaling factors are computed to equilibrate */ /* the system: */ /* diag(S) * A * diag(S) * inv(diag(S)) * X = diag(S) * B */ /* Whether or not the system will be equilibrated depends on the */ /* scaling of the matrix A, but if equilibration is used, A is */ /* overwritten by diag(S)*A*diag(S) and B by diag(S)*B. */ /* 2. If FACT = 'N' or 'E', the Cholesky decomposition is used to */ /* factor the matrix A (after equilibration if FACT = 'E') as */ /* A = U**H * U, if UPLO = 'U', or */ /* A = L * L**H, if UPLO = 'L', */ /* where U is an upper triangular band matrix, and L is a lower */ /* triangular band matrix. */ /* 3. If the leading i-by-i principal minor is not positive definite, */ /* then the routine returns with INFO = i. Otherwise, the factored */ /* form of A is used to estimate the condition number of the matrix */ /* A. If the reciprocal of the condition number is less than machine */ /* precision, INFO = N+1 is returned as a warning, but the routine */ /* still goes on to solve for X and compute error bounds as */ /* described below. */ /* 4. The system of equations is solved for X using the factored form */ /* of A. */ /* 5. Iterative refinement is applied to improve the computed solution */ /* matrix and calculate error bounds and backward error estimates */ /* for it. */ /* 6. If equilibration was used, the matrix X is premultiplied by */ /* diag(S) so that it solves the original system before */ /* equilibration. */ /* Arguments */ /* ========= */ /* FACT (input) CHARACTER*1 */ /* Specifies whether or not the factored form of the matrix A is */ /* supplied on entry, and if not, whether the matrix A should be */ /* equilibrated before it is factored. */ /* = 'F': On entry, AFB contains the factored form of A. */ /* If EQUED = 'Y', the matrix A has been equilibrated */ /* with scaling factors given by S. AB and AFB will not */ /* be modified. */ /* = 'N': The matrix A will be copied to AFB and factored. */ /* = 'E': The matrix A will be equilibrated if necessary, then */ /* copied to AFB and factored. */ /* UPLO (input) CHARACTER*1 */ /* = 'U': Upper triangle of A is stored; */ /* = 'L': Lower triangle of A is stored. */ /* N (input) INTEGER */ /* The number of linear equations, i.e., 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 matrices B and X. NRHS >= 0. */ /* AB (input/output) COMPLEX array, dimension (LDAB,N) */ /* On entry, the upper or lower triangle of the Hermitian band */ /* matrix A, stored in the first KD+1 rows of the array, except */ /* if FACT = 'F' and EQUED = 'Y', then A must contain the */ /* equilibrated matrix diag(S)*A*diag(S). 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). */ /* See below for further details. */ /* On exit, if FACT = 'E' and EQUED = 'Y', A is overwritten by */ /* diag(S)*A*diag(S). */ /* LDAB (input) INTEGER */ /* The leading dimension of the array A. LDAB >= KD+1. */ /* AFB (input or output) COMPLEX array, dimension (LDAFB,N) */ /* If FACT = 'F', then AFB is an input argument and on entry */ /* contains the triangular factor U or L from the Cholesky */ /* factorization A = U**H*U or A = L*L**H of the band matrix */ /* A, in the same storage format as A (see AB). If EQUED = 'Y', */ /* then AFB is the factored form of the equilibrated matrix A. */ /* If FACT = 'N', then AFB is an output argument and on exit */ /* returns the triangular factor U or L from the Cholesky */ /* factorization A = U**H*U or A = L*L**H. */ /* If FACT = 'E', then AFB is an output argument and on exit */ /* returns the triangular factor U or L from the Cholesky */ /* factorization A = U**H*U or A = L*L**H of the equilibrated */ /* matrix A (see the description of A for the form of the */ /* equilibrated matrix). */ /* LDAFB (input) INTEGER */ /* The leading dimension of the array AFB. LDAFB >= KD+1. */ /* EQUED (input or output) CHARACTER*1 */ /* Specifies the form of equilibration that was done. */ /* = 'N': No equilibration (always true if FACT = 'N'). */ /* = 'Y': Equilibration was done, i.e., A has been replaced by */ /* diag(S) * A * diag(S). */ /* EQUED is an input argument if FACT = 'F'; otherwise, it is an */ /* output argument. */ /* S (input or output) REAL array, dimension (N) */ /* The scale factors for A; not accessed if EQUED = 'N'. S is */ /* an input argument if FACT = 'F'; otherwise, S is an output */ /* argument. If FACT = 'F' and EQUED = 'Y', each element of S */ /* must be positive. */ /* B (input/output) COMPLEX array, dimension (LDB,NRHS) */ /* On entry, the N-by-NRHS right hand side matrix B. */ /* On exit, if EQUED = 'N', B is not modified; if EQUED = 'Y', */ /* B is overwritten by diag(S) * B. */ /* LDB (input) INTEGER */ /* The leading dimension of the array B. LDB >= MAX(1,N). */ /* X (output) COMPLEX array, dimension (LDX,NRHS) */ /* If INFO = 0 or INFO = N+1, the N-by-NRHS solution matrix X to */ /* the original system of equations. Note that if EQUED = 'Y', */ /* A and B are modified on exit, and the solution to the */ /* equilibrated system is inv(diag(S))*X. */ /* LDX (input) INTEGER */ /* The leading dimension of the array X. LDX >= MAX(1,N). */ /* RCOND (output) REAL */ /* The estimate of the reciprocal condition number of the matrix */ /* A after equilibration (if done). If RCOND is less than the */ /* machine precision (in particular, if RCOND = 0), the matrix */ /* is singular to working precision. This condition is */ /* indicated by a return code of INFO > 0. */ /* FERR (output) REAL 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) REAL 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 array, dimension (2*N) */ /* RWORK (workspace) REAL array, dimension (N) */ /* INFO (output) INTEGER */ /* = 0: successful exit */ /* < 0: if INFO = -i, the i-th argument had an illegal value */ /* > 0: if INFO = i, and i is */ /* <= N: the leading minor of order i of A is */ /* not positive definite, so the factorization */ /* could not be completed, and the solution has not */ /* been computed. RCOND = 0 is returned. */ /* = N+1: U is nonsingular, but RCOND is less than machine */ /* precision, meaning that the matrix is singular */ /* to working precision. Nevertheless, the */ /* solution and error bounds are computed because */ /* there are a number of situations where the */ /* computed solution can be more accurate than the */ /* value of RCOND would suggest. */ /* Further Details */ /* =============== */ /* The band storage scheme is illustrated by the following example, when */ /* N = 6, KD = 2, and UPLO = 'U': */ /* Two-dimensional storage of the Hermitian matrix A: */ /* a11 a12 a13 */ /* a22 a23 a24 */ /* a33 a34 a35 */ /* a44 a45 a46 */ /* a55 a56 */ /* (aij=conjg(aji)) a66 */ /* Band storage of the upper triangle of A: */ /* * * a13 a24 a35 a46 */ /* * a12 a23 a34 a45 a56 */ /* a11 a22 a33 a44 a55 a66 */ /* Similarly, if UPLO = 'L' the format of A is as follows: */ /* a11 a22 a33 a44 a55 a66 */ /* a21 a32 a43 a54 a65 * */ /* a31 a42 a53 a64 * * */ /* Array elements marked * are not used by the routine. */ /* ===================================================================== */ /* .. Parameters .. */ /* .. */ /* .. Local Scalars .. */ /* .. */ /* .. External Functions .. */ /* .. */ /* .. External Subroutines .. */ /* .. */ /* .. Intrinsic Functions .. */ /* .. */ /* .. Executable Statements .. */ /* Parameter adjustments */ ab_dim1 = *ldab; ab_offset = 1 + ab_dim1; ab -= ab_offset; afb_dim1 = *ldafb; afb_offset = 1 + afb_dim1; afb -= afb_offset; --s; 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; nofact = lsame_(fact, "N"); equil = lsame_(fact, "E"); upper = lsame_(uplo, "U"); if (nofact || equil) { *(unsigned char *)equed = 'N'; rcequ = FALSE; } else { rcequ = lsame_(equed, "Y"); smlnum = slamch_("Safe minimum"); bignum = 1.f / smlnum; } /* Test the input parameters. */ if (! nofact && ! equil && ! lsame_(fact, "F")) { *info = -1; } else if (! upper && ! lsame_(uplo, "L")) { *info = -2; } else if (*n < 0) { *info = -3; } else if (*kd < 0) { *info = -4; } else if (*nrhs < 0) { *info = -5; } else if (*ldab < *kd + 1) { *info = -7; } else if (*ldafb < *kd + 1) { *info = -9; } else if (lsame_(fact, "F") && ! (rcequ || lsame_( equed, "N"))) { *info = -10; } else { if (rcequ) { smin = bignum; smax = 0.f; i__1 = *n; for (j = 1; j <= i__1; ++j) { /* Computing MIN */ r__1 = smin, r__2 = s[j]; smin = MIN(r__1,r__2); /* Computing MAX */ r__1 = smax, r__2 = s[j]; smax = MAX(r__1,r__2); /* L10: */ } if (smin <= 0.f) { *info = -11; } else if (*n > 0) { scond = MAX(smin,smlnum) / MIN(smax,bignum); } else { scond = 1.f; } } if (*info == 0) { if (*ldb < MAX(1,*n)) { *info = -13; } else if (*ldx < MAX(1,*n)) { *info = -15; } } } if (*info != 0) { i__1 = -(*info); xerbla_("CPBSVX", &i__1); return 0; } if (equil) { /* Compute row and column scalings to equilibrate the matrix A. */ cpbequ_(uplo, n, kd, &ab[ab_offset], ldab, &s[1], &scond, &amax, & infequ); if (infequ == 0) { /* Equilibrate the matrix. */ claqhb_(uplo, n, kd, &ab[ab_offset], ldab, &s[1], &scond, &amax, equed); rcequ = lsame_(equed, "Y"); } } /* Scale the right-hand side. */ if (rcequ) { i__1 = *nrhs; for (j = 1; j <= i__1; ++j) { i__2 = *n; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * b_dim1; i__4 = i__; i__5 = i__ + j * b_dim1; q__1.r = s[i__4] * b[i__5].r, q__1.i = s[i__4] * b[i__5].i; b[i__3].r = q__1.r, b[i__3].i = q__1.i; /* L20: */ } /* L30: */ } } if (nofact || equil) { /* Compute the Cholesky factorization A = U'*U or A = L*L'. */ if (upper) { i__1 = *n; for (j = 1; j <= i__1; ++j) { /* Computing MAX */ i__2 = j - *kd; j1 = MAX(i__2,1); i__2 = j - j1 + 1; ccopy_(&i__2, &ab[*kd + 1 - j + j1 + j * ab_dim1], &c__1, & afb[*kd + 1 - j + j1 + j * afb_dim1], &c__1); /* L40: */ } } else { i__1 = *n; for (j = 1; j <= i__1; ++j) { /* Computing MIN */ i__2 = j + *kd; j2 = MIN(i__2,*n); i__2 = j2 - j + 1; ccopy_(&i__2, &ab[j * ab_dim1 + 1], &c__1, &afb[j * afb_dim1 + 1], &c__1); /* L50: */ } } cpbtrf_(uplo, n, kd, &afb[afb_offset], ldafb, info); /* Return if INFO is non-zero. */ if (*info > 0) { *rcond = 0.f; return 0; } } /* Compute the norm of the matrix A. */ anorm = clanhb_("1", uplo, n, kd, &ab[ab_offset], ldab, &rwork[1]); /* Compute the reciprocal of the condition number of A. */ cpbcon_(uplo, n, kd, &afb[afb_offset], ldafb, &anorm, rcond, &work[1], & rwork[1], info); /* Compute the solution matrix X. */ clacpy_("Full", n, nrhs, &b[b_offset], ldb, &x[x_offset], ldx); cpbtrs_(uplo, n, kd, nrhs, &afb[afb_offset], ldafb, &x[x_offset], ldx, info); /* Use iterative refinement to improve the computed solution and */ /* compute error bounds and backward error estimates for it. */ cpbrfs_(uplo, n, kd, nrhs, &ab[ab_offset], ldab, &afb[afb_offset], ldafb, &b[b_offset], ldb, &x[x_offset], ldx, &ferr[1], &berr[1], &work[1] , &rwork[1], info); /* Transform the solution matrix X to a solution of the original */ /* system. */ if (rcequ) { i__1 = *nrhs; for (j = 1; j <= i__1; ++j) { i__2 = *n; for (i__ = 1; i__ <= i__2; ++i__) { i__3 = i__ + j * x_dim1; i__4 = i__; i__5 = i__ + j * x_dim1; q__1.r = s[i__4] * x[i__5].r, q__1.i = s[i__4] * x[i__5].i; x[i__3].r = q__1.r, x[i__3].i = q__1.i; /* L60: */ } /* L70: */ } i__1 = *nrhs; for (j = 1; j <= i__1; ++j) { ferr[j] /= scond; /* L80: */ } } /* Set INFO = N+1 if the matrix is singular to working precision. */ if (*rcond < slamch_("Epsilon")) { *info = *n + 1; } return 0; /* End of CPBSVX */ } /* cpbsvx_ */