int sspcon_(char *uplo, int *n, float *ap, int *ipiv,
float *anorm, float *rcond, float *work, int *iwork, int *info)
{
/* System generated locals */
int i__1;
/* Local variables */
int i__, ip, kase;
extern int lsame_(char *, char *);
int isave[3];
int upper;
extern int slacn2_(int *, float *, float *, int *,
float *, int *, int *), xerbla_(char *, int *);
float ainvnm;
extern int ssptrs_(char *, int *, int *, float *,
int *, float *, int *, int *);
/* -- LAPACK routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* Modified to call SLACN2 in place of SLACON, 5 Feb 03, SJH. */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* SSPCON estimates the reciprocal of the condition number (in the */
/* 1-norm) of a float symmetric packed matrix A using the factorization */
/* A = U*D*U**T or A = L*D*L**T computed by SSPTRF. */
/* An estimate is obtained for norm(inv(A)), and the reciprocal of the */
/* condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))). */
/* Arguments */
/* ========= */
/* UPLO (input) CHARACTER*1 */
/* Specifies whether the details of the factorization are stored */
/* as an upper or lower triangular matrix. */
/* = 'U': Upper triangular, form is A = U*D*U**T; */
/* = 'L': Lower triangular, form is A = L*D*L**T. */
/* N (input) INTEGER */
/* The order of the matrix A. N >= 0. */
/* AP (input) REAL array, dimension (N*(N+1)/2) */
/* The block diagonal matrix D and the multipliers used to */
/* obtain the factor U or L as computed by SSPTRF, stored as a */
/* packed triangular matrix. */
/* IPIV (input) INTEGER array, dimension (N) */
/* Details of the interchanges and the block structure of D */
/* as determined by SSPTRF. */
/* ANORM (input) REAL */
/* The 1-norm of the original matrix A. */
/* RCOND (output) REAL */
/* The reciprocal of the condition number of the matrix A, */
/* computed as RCOND = 1/(ANORM * AINVNM), where AINVNM is an */
/* estimate of the 1-norm of inv(A) computed in this routine. */
/* WORK (workspace) REAL array, dimension (2*N) */
/* IWORK (workspace) INTEGER array, dimension (N) */
/* INFO (output) INTEGER */
/* = 0: successful exit */
/* < 0: if INFO = -i, the i-th argument had an illegal value */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. Local Arrays .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Executable Statements .. */
/* Test the input parameters. */
/* Parameter adjustments */
--iwork;
--work;
--ipiv;
--ap;
/* Function Body */
*info = 0;
upper = lsame_(uplo, "U");
if (! upper && ! lsame_(uplo, "L")) {
*info = -1;
} else if (*n < 0) {
*info = -2;
} else if (*anorm < 0.f) {
*info = -5;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("SSPCON", &i__1);
return 0;
}
/* Quick return if possible */
*rcond = 0.f;
if (*n == 0) {
*rcond = 1.f;
return 0;
} else if (*anorm <= 0.f) {
return 0;
}
/* Check that the diagonal matrix D is nonsingular. */
if (upper) {
/* Upper triangular storage: examine D from bottom to top */
ip = *n * (*n + 1) / 2;
for (i__ = *n; i__ >= 1; --i__) {
if (ipiv[i__] > 0 && ap[ip] == 0.f) {
return 0;
}
ip -= i__;
/* L10: */
}
} else {
/* Lower triangular storage: examine D from top to bottom. */
ip = 1;
i__1 = *n;
for (i__ = 1; i__ <= i__1; ++i__) {
if (ipiv[i__] > 0 && ap[ip] == 0.f) {
return 0;
}
ip = ip + *n - i__ + 1;
/* L20: */
}
}
/* Estimate the 1-norm of the inverse. */
kase = 0;
L30:
slacn2_(n, &work[*n + 1], &work[1], &iwork[1], &ainvnm, &kase, isave);
if (kase != 0) {
/* Multiply by inv(L*D*L') or inv(U*D*U'). */
ssptrs_(uplo, n, &c__1, &ap[1], &ipiv[1], &work[1], n, info);
goto L30;
}
/* Compute the estimate of the reciprocal condition number. */
if (ainvnm != 0.f) {
*rcond = 1.f / ainvnm / *anorm;
}
return 0;
/* End of SSPCON */
} /* sspcon_ */
/* Subroutine */ int sspsv_(char *uplo, integer *n, integer *nrhs, real *ap,
integer *ipiv, real *b, integer *ldb, integer *info)
{
/* -- LAPACK driver routine (version 3.0) --
Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
Courant Institute, Argonne National Lab, and Rice University
March 31, 1993
Purpose
=======
SSPSV computes the solution to a real system of linear equations
A * X = B,
where A is an N-by-N symmetric matrix stored in packed format and X
and B are N-by-NRHS matrices.
The diagonal pivoting method is used to factor A as
A = U * D * U**T, if UPLO = 'U', or
A = L * D * L**T, if UPLO = 'L',
where U (or L) is a product of permutation and unit upper (lower)
triangular matrices, D is symmetric and block diagonal with 1-by-1
and 2-by-2 diagonal blocks. The factored form of A is then used to
solve the system of equations A * X = B.
Arguments
=========
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.
NRHS (input) INTEGER
The number of right hand sides, i.e., the number of columns
of the matrix B. NRHS >= 0.
AP (input/output) REAL array, dimension (N*(N+1)/2)
On entry, the upper or lower triangle of the symmetric matrix
A, packed columnwise in a linear array. The j-th column of A
is stored in the array AP as follows:
if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n.
See below for further details.
On exit, the block diagonal matrix D and the multipliers used
to obtain the factor U or L from the factorization
A = U*D*U**T or A = L*D*L**T as computed by SSPTRF, stored as
a packed triangular matrix in the same storage format as A.
IPIV (output) INTEGER array, dimension (N)
Details of the interchanges and the block structure of D, as
determined by SSPTRF. If IPIV(k) > 0, then rows and columns
k and IPIV(k) were interchanged, and D(k,k) is a 1-by-1
diagonal block. If UPLO = 'U' and IPIV(k) = IPIV(k-1) < 0,
then rows and columns k-1 and -IPIV(k) were interchanged and
D(k-1:k,k-1:k) is a 2-by-2 diagonal block. If UPLO = 'L' and
IPIV(k) = IPIV(k+1) < 0, then rows and columns k+1 and
-IPIV(k) were interchanged and D(k:k+1,k:k+1) is a 2-by-2
diagonal block.
B (input/output) REAL array, dimension (LDB,NRHS)
On entry, the N-by-NRHS right hand side matrix B.
On exit, if INFO = 0, the N-by-NRHS 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, D(i,i) is exactly zero. The factorization
has been completed, but the block diagonal matrix D is
exactly singular, so the solution could not be
computed.
Further Details
===============
The packed storage scheme is illustrated by the following example
when N = 4, UPLO = 'U':
Two-dimensional storage of the symmetric matrix A:
a11 a12 a13 a14
a22 a23 a24
a33 a34 (aij = aji)
a44
Packed storage of the upper triangle of A:
AP = [ a11, a12, a22, a13, a23, a33, a14, a24, a34, a44 ]
=====================================================================
Test the input parameters.
Parameter adjustments */
/* System generated locals */
integer b_dim1, b_offset, i__1;
/* Local variables */
extern logical lsame_(char *, char *);
extern /* Subroutine */ int xerbla_(char *, integer *), ssptrf_(
char *, integer *, real *, integer *, integer *), ssptrs_(
char *, integer *, integer *, real *, integer *, real *, integer *
, integer *);
--ap;
--ipiv;
b_dim1 = *ldb;
b_offset = 1 + b_dim1 * 1;
b -= b_offset;
/* Function Body */
*info = 0;
if (! lsame_(uplo, "U") && ! lsame_(uplo, "L")) {
*info = -1;
} else if (*n < 0) {
*info = -2;
} else if (*nrhs < 0) {
*info = -3;
} else if (*ldb < max(1,*n)) {
*info = -7;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("SSPSV ", &i__1);
return 0;
}
/* Compute the factorization A = U*D*U' or A = L*D*L'. */
ssptrf_(uplo, n, &ap[1], &ipiv[1], info);
if (*info == 0) {
/* Solve the system A*X = B, overwriting B with X. */
ssptrs_(uplo, n, nrhs, &ap[1], &ipiv[1], &b[b_offset], ldb, info);
}
return 0;
/* End of SSPSV */
} /* sspsv_ */
int main(void)
{
/* Local scalars */
char uplo, uplo_i;
lapack_int n, n_i;
lapack_int nrhs, nrhs_i;
lapack_int ldb, ldb_i;
lapack_int ldb_r;
lapack_int info, info_i;
lapack_int i;
int failed;
/* Local arrays */
float *ap = NULL, *ap_i = NULL;
lapack_int *ipiv = NULL, *ipiv_i = NULL;
float *b = NULL, *b_i = NULL;
float *b_save = NULL;
float *ap_r = NULL;
float *b_r = NULL;
/* Iniitialize the scalar parameters */
init_scalars_ssptrs( &uplo, &n, &nrhs, &ldb );
ldb_r = nrhs+2;
uplo_i = uplo;
n_i = n;
nrhs_i = nrhs;
ldb_i = ldb;
/* Allocate memory for the LAPACK routine arrays */
ap = (float *)LAPACKE_malloc( ((n*(n+1)/2)) * sizeof(float) );
ipiv = (lapack_int *)LAPACKE_malloc( n * sizeof(lapack_int) );
b = (float *)LAPACKE_malloc( ldb*nrhs * sizeof(float) );
/* Allocate memory for the C interface function arrays */
ap_i = (float *)LAPACKE_malloc( ((n*(n+1)/2)) * sizeof(float) );
ipiv_i = (lapack_int *)LAPACKE_malloc( n * sizeof(lapack_int) );
b_i = (float *)LAPACKE_malloc( ldb*nrhs * sizeof(float) );
/* Allocate memory for the backup arrays */
b_save = (float *)LAPACKE_malloc( ldb*nrhs * sizeof(float) );
/* Allocate memory for the row-major arrays */
ap_r = (float *)LAPACKE_malloc( n*(n+1)/2 * sizeof(float) );
b_r = (float *)LAPACKE_malloc( n*(nrhs+2) * sizeof(float) );
/* Initialize input arrays */
init_ap( (n*(n+1)/2), ap );
init_ipiv( n, ipiv );
init_b( ldb*nrhs, b );
/* Backup the ouptut arrays */
for( i = 0; i < ldb*nrhs; i++ ) {
b_save[i] = b[i];
}
/* Call the LAPACK routine */
ssptrs_( &uplo, &n, &nrhs, ap, ipiv, b, &ldb, &info );
/* Initialize input data, call the column-major middle-level
* interface to LAPACK routine and check the results */
for( i = 0; i < (n*(n+1)/2); i++ ) {
ap_i[i] = ap[i];
}
for( i = 0; i < n; i++ ) {
ipiv_i[i] = ipiv[i];
}
for( i = 0; i < ldb*nrhs; i++ ) {
b_i[i] = b_save[i];
}
info_i = LAPACKE_ssptrs_work( LAPACK_COL_MAJOR, uplo_i, n_i, nrhs_i, ap_i,
ipiv_i, b_i, ldb_i );
failed = compare_ssptrs( b, b_i, info, info_i, ldb, nrhs );
if( failed == 0 ) {
printf( "PASSED: column-major middle-level interface to ssptrs\n" );
} else {
printf( "FAILED: column-major middle-level interface to ssptrs\n" );
}
/* Initialize input data, call the column-major high-level
* interface to LAPACK routine and check the results */
for( i = 0; i < (n*(n+1)/2); i++ ) {
ap_i[i] = ap[i];
}
for( i = 0; i < n; i++ ) {
ipiv_i[i] = ipiv[i];
}
for( i = 0; i < ldb*nrhs; i++ ) {
b_i[i] = b_save[i];
}
info_i = LAPACKE_ssptrs( LAPACK_COL_MAJOR, uplo_i, n_i, nrhs_i, ap_i,
ipiv_i, b_i, ldb_i );
failed = compare_ssptrs( b, b_i, info, info_i, ldb, nrhs );
if( failed == 0 ) {
printf( "PASSED: column-major high-level interface to ssptrs\n" );
} else {
printf( "FAILED: column-major high-level interface to ssptrs\n" );
}
/* Initialize input data, call the row-major middle-level
* interface to LAPACK routine and check the results */
for( i = 0; i < (n*(n+1)/2); i++ ) {
ap_i[i] = ap[i];
}
for( i = 0; i < n; i++ ) {
ipiv_i[i] = ipiv[i];
}
for( i = 0; i < ldb*nrhs; i++ ) {
b_i[i] = b_save[i];
}
LAPACKE_spp_trans( LAPACK_COL_MAJOR, uplo, n, ap_i, ap_r );
LAPACKE_sge_trans( LAPACK_COL_MAJOR, n, nrhs, b_i, ldb, b_r, nrhs+2 );
info_i = LAPACKE_ssptrs_work( LAPACK_ROW_MAJOR, uplo_i, n_i, nrhs_i, ap_r,
ipiv_i, b_r, ldb_r );
LAPACKE_sge_trans( LAPACK_ROW_MAJOR, n, nrhs, b_r, nrhs+2, b_i, ldb );
failed = compare_ssptrs( b, b_i, info, info_i, ldb, nrhs );
if( failed == 0 ) {
printf( "PASSED: row-major middle-level interface to ssptrs\n" );
} else {
printf( "FAILED: row-major middle-level interface to ssptrs\n" );
}
/* Initialize input data, call the row-major high-level
* interface to LAPACK routine and check the results */
for( i = 0; i < (n*(n+1)/2); i++ ) {
ap_i[i] = ap[i];
}
for( i = 0; i < n; i++ ) {
ipiv_i[i] = ipiv[i];
}
for( i = 0; i < ldb*nrhs; i++ ) {
b_i[i] = b_save[i];
}
/* Init row_major arrays */
LAPACKE_spp_trans( LAPACK_COL_MAJOR, uplo, n, ap_i, ap_r );
LAPACKE_sge_trans( LAPACK_COL_MAJOR, n, nrhs, b_i, ldb, b_r, nrhs+2 );
info_i = LAPACKE_ssptrs( LAPACK_ROW_MAJOR, uplo_i, n_i, nrhs_i, ap_r,
ipiv_i, b_r, ldb_r );
LAPACKE_sge_trans( LAPACK_ROW_MAJOR, n, nrhs, b_r, nrhs+2, b_i, ldb );
failed = compare_ssptrs( b, b_i, info, info_i, ldb, nrhs );
if( failed == 0 ) {
printf( "PASSED: row-major high-level interface to ssptrs\n" );
} else {
printf( "FAILED: row-major high-level interface to ssptrs\n" );
}
/* Release memory */
if( ap != NULL ) {
LAPACKE_free( ap );
}
if( ap_i != NULL ) {
LAPACKE_free( ap_i );
}
if( ap_r != NULL ) {
LAPACKE_free( ap_r );
}
if( ipiv != NULL ) {
LAPACKE_free( ipiv );
}
if( ipiv_i != NULL ) {
LAPACKE_free( ipiv_i );
}
if( b != NULL ) {
LAPACKE_free( b );
}
if( b_i != NULL ) {
LAPACKE_free( b_i );
}
if( b_r != NULL ) {
LAPACKE_free( b_r );
}
if( b_save != NULL ) {
LAPACKE_free( b_save );
}
return 0;
}
/* Subroutine */ int schksp_(logical *dotype, integer *nn, integer *nval,
integer *nns, integer *nsval, real *thresh, logical *tsterr, integer *
nmax, real *a, real *afac, real *ainv, real *b, real *x, real *xact,
real *work, real *rwork, integer *iwork, integer *nout)
{
/* Initialized data */
static integer iseedy[4] = { 1988,1989,1990,1991 };
static char uplos[1*2] = "U" "L";
/* Format strings */
static char fmt_9999[] = "(\002 UPLO = '\002,a1,\002', N =\002,i5,\002, "
"type \002,i2,\002, test \002,i2,\002, ratio =\002,g12.5)";
static char fmt_9998[] = "(\002 UPLO = '\002,a1,\002', N =\002,i5,\002, "
"NRHS=\002,i3,\002, type \002,i2,\002, test(\002,i2,\002) =\002,g"
"12.5)";
/* System generated locals */
integer i__1, i__2, i__3, i__4;
/* Builtin functions */
/* Subroutine */ int s_copy(char *, char *, ftnlen, ftnlen);
integer s_wsfe(cilist *), do_fio(integer *, char *, ftnlen), e_wsfe(void);
/* Local variables */
integer i__, j, k, n, i1, i2, in, kl, ku, nt, lda, npp, ioff, mode, imat,
info;
char path[3], dist[1];
integer irhs, nrhs;
char uplo[1], type__[1];
integer nrun;
extern /* Subroutine */ int alahd_(integer *, char *);
integer nfail, iseed[4];
extern logical lsame_(char *, char *);
real rcond;
extern /* Subroutine */ int sget04_(integer *, integer *, real *, integer
*, real *, integer *, real *, real *);
integer nimat;
extern doublereal sget06_(real *, real *);
real anorm;
integer iuplo, izero, nerrs;
extern /* Subroutine */ int sppt02_(char *, integer *, integer *, real *,
real *, integer *, real *, integer *, real *, real *),
scopy_(integer *, real *, integer *, real *, integer *), sppt03_(
char *, integer *, real *, real *, real *, integer *, real *,
real *, real *), sppt05_(char *, integer *, integer *,
real *, real *, integer *, real *, integer *, real *, integer *,
real *, real *, real *), sspt01_(char *, integer *, real *
, real *, integer *, real *, integer *, real *, real *);
logical zerot;
char xtype[1];
extern /* Subroutine */ int slatb4_(char *, integer *, integer *, integer
*, char *, integer *, integer *, real *, integer *, real *, char *
), alaerh_(char *, char *, integer *,
integer *, char *, integer *, integer *, integer *, integer *,
integer *, integer *, integer *, integer *, integer *);
real rcondc;
char packit[1];
extern /* Subroutine */ int alasum_(char *, integer *, integer *, integer
*, integer *);
real cndnum;
logical trfcon;
extern /* Subroutine */ int slacpy_(char *, integer *, integer *, real *,
integer *, real *, integer *), slarhs_(char *, char *,
char *, char *, integer *, integer *, integer *, integer *,
integer *, real *, integer *, real *, integer *, real *, integer *
, integer *, integer *);
extern doublereal slansp_(char *, char *, integer *, real *, real *);
extern /* Subroutine */ int slatms_(integer *, integer *, char *, integer
*, char *, real *, integer *, real *, real *, integer *, integer *
, char *, real *, integer *, real *, integer *), sspcon_(char *, integer *, real *, integer *, real *,
real *, real *, integer *, integer *);
real result[8];
extern /* Subroutine */ int ssprfs_(char *, integer *, integer *, real *,
real *, integer *, real *, integer *, real *, integer *, real *,
real *, real *, integer *, integer *), ssptrf_(char *,
integer *, real *, integer *, integer *), ssptri_(char *,
integer *, real *, integer *, real *, integer *), serrsy_(
char *, integer *), ssptrs_(char *, integer *, integer *,
real *, integer *, real *, integer *, integer *);
/* Fortran I/O blocks */
static cilist io___38 = { 0, 0, 0, fmt_9999, 0 };
static cilist io___41 = { 0, 0, 0, fmt_9998, 0 };
static cilist io___43 = { 0, 0, 0, fmt_9999, 0 };
/* -- LAPACK test routine (version 3.1) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* SCHKSP tests SSPTRF, -TRI, -TRS, -RFS, and -CON */
/* 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. */
/* 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) 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) REAL array, dimension */
/* (NMAX*(NMAX+1)/2) */
/* AFAC (workspace) REAL array, dimension */
/* (NMAX*(NMAX+1)/2) */
/* AINV (workspace) REAL array, dimension */
/* (NMAX*(NMAX+1)/2) */
/* B (workspace) REAL array, dimension (NMAX*NSMAX) */
/* where NSMAX is the largest entry in NSVAL. */
/* X (workspace) REAL array, dimension (NMAX*NSMAX) */
/* XACT (workspace) REAL array, dimension (NMAX*NSMAX) */
/* WORK (workspace) REAL array, dimension */
/* (NMAX*max(2,NSMAX)) */
/* RWORK (workspace) REAL array, */
/* dimension (NMAX+2*NSMAX) */
/* IWORK (workspace) INTEGER array, dimension (2*NMAX) */
/* 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 */
--iwork;
--rwork;
--work;
--xact;
--x;
--b;
--ainv;
--afac;
--a;
--nsval;
--nval;
--dotype;
/* Function Body */
/* .. */
/* .. Executable Statements .. */
/* Initialize constants and the random number seed. */
s_copy(path, "Single precision", (ftnlen)1, (ftnlen)16);
s_copy(path + 1, "SP", (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) {
serrsy_(path, nout);
}
infoc_1.infot = 0;
/* 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';
nimat = 10;
if (n <= 0) {
nimat = 1;
}
izero = 0;
i__2 = nimat;
for (imat = 1; imat <= i__2; ++imat) {
/* Do the tests only if DOTYPE( IMAT ) is true. */
if (! dotype[imat]) {
goto L160;
}
/* Skip types 3, 4, 5, or 6 if the matrix size is too small. */
zerot = imat >= 3 && imat <= 6;
if (zerot && n < imat - 2) {
goto L160;
}
/* Do first for UPLO = 'U', then for UPLO = 'L' */
for (iuplo = 1; iuplo <= 2; ++iuplo) {
*(unsigned char *)uplo = *(unsigned char *)&uplos[iuplo - 1];
if (lsame_(uplo, "U")) {
*(unsigned char *)packit = 'C';
} else {
*(unsigned char *)packit = 'R';
}
/* Set up parameters with SLATB4 and generate a test matrix */
/* with SLATMS. */
slatb4_(path, &imat, &n, &n, type__, &kl, &ku, &anorm, &mode,
&cndnum, dist);
s_copy(srnamc_1.srnamt, "SLATMS", (ftnlen)6, (ftnlen)6);
slatms_(&n, &n, dist, iseed, type__, &rwork[1], &mode, &
cndnum, &anorm, &kl, &ku, packit, &a[1], &lda, &work[
1], &info);
/* Check error code from SLATMS. */
if (info != 0) {
alaerh_(path, "SLATMS", &info, &c__0, uplo, &n, &n, &c_n1,
&c_n1, &c_n1, &imat, &nfail, &nerrs, nout);
goto L150;
}
/* For types 3-6, zero one or more rows and columns of */
/* the matrix to test that INFO is returned correctly. */
if (zerot) {
if (imat == 3) {
izero = 1;
} else if (imat == 4) {
izero = n;
} else {
izero = n / 2 + 1;
}
if (imat < 6) {
/* Set row and column IZERO to zero. */
if (iuplo == 1) {
ioff = (izero - 1) * izero / 2;
i__3 = izero - 1;
for (i__ = 1; i__ <= i__3; ++i__) {
a[ioff + i__] = 0.f;
/* L20: */
}
ioff += izero;
i__3 = n;
for (i__ = izero; i__ <= i__3; ++i__) {
a[ioff] = 0.f;
ioff += i__;
/* L30: */
}
} else {
ioff = izero;
i__3 = izero - 1;
for (i__ = 1; i__ <= i__3; ++i__) {
a[ioff] = 0.f;
ioff = ioff + n - i__;
/* L40: */
}
ioff -= izero;
i__3 = n;
for (i__ = izero; i__ <= i__3; ++i__) {
a[ioff + i__] = 0.f;
/* L50: */
}
}
} else {
ioff = 0;
if (iuplo == 1) {
/* Set the first IZERO rows and columns to zero. */
i__3 = n;
for (j = 1; j <= i__3; ++j) {
i2 = min(j,izero);
i__4 = i2;
for (i__ = 1; i__ <= i__4; ++i__) {
a[ioff + i__] = 0.f;
/* L60: */
}
ioff += j;
/* L70: */
}
} else {
/* Set the last IZERO rows and columns to zero. */
i__3 = n;
for (j = 1; j <= i__3; ++j) {
i1 = max(j,izero);
i__4 = n;
for (i__ = i1; i__ <= i__4; ++i__) {
a[ioff + i__] = 0.f;
/* L80: */
}
ioff = ioff + n - j;
/* L90: */
}
}
}
} else {
izero = 0;
}
/* Compute the L*D*L' or U*D*U' factorization of the matrix. */
npp = n * (n + 1) / 2;
scopy_(&npp, &a[1], &c__1, &afac[1], &c__1);
s_copy(srnamc_1.srnamt, "SSPTRF", (ftnlen)6, (ftnlen)6);
ssptrf_(uplo, &n, &afac[1], &iwork[1], &info);
/* Adjust the expected value of INFO to account for */
/* pivoting. */
k = izero;
if (k > 0) {
L100:
if (iwork[k] < 0) {
if (iwork[k] != -k) {
k = -iwork[k];
goto L100;
}
} else if (iwork[k] != k) {
k = iwork[k];
goto L100;
}
}
/* Check error code from SSPTRF. */
if (info != k) {
alaerh_(path, "SSPTRF", &info, &k, uplo, &n, &n, &c_n1, &
c_n1, &c_n1, &imat, &nfail, &nerrs, nout);
}
if (info != 0) {
trfcon = TRUE_;
} else {
trfcon = FALSE_;
}
/* + TEST 1 */
/* Reconstruct matrix from factors and compute residual. */
sspt01_(uplo, &n, &a[1], &afac[1], &iwork[1], &ainv[1], &lda,
&rwork[1], result);
nt = 1;
/* + TEST 2 */
/* Form the inverse and compute the residual. */
if (! trfcon) {
scopy_(&npp, &afac[1], &c__1, &ainv[1], &c__1);
s_copy(srnamc_1.srnamt, "SSPTRI", (ftnlen)6, (ftnlen)6);
ssptri_(uplo, &n, &ainv[1], &iwork[1], &work[1], &info);
/* Check error code from SSPTRI. */
if (info != 0) {
alaerh_(path, "SSPTRI", &info, &c__0, uplo, &n, &n, &
c_n1, &c_n1, &c_n1, &imat, &nfail, &nerrs,
nout);
}
sppt03_(uplo, &n, &a[1], &ainv[1], &work[1], &lda, &rwork[
1], &rcondc, &result[1]);
nt = 2;
}
/* Print information about the tests that did not pass */
/* the threshold. */
i__3 = nt;
for (k = 1; k <= i__3; ++k) {
if (result[k - 1] >= *thresh) {
if (nfail == 0 && nerrs == 0) {
alahd_(nout, path);
}
io___38.ciunit = *nout;
s_wsfe(&io___38);
do_fio(&c__1, uplo, (ftnlen)1);
do_fio(&c__1, (char *)&n, (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;
}
/* L110: */
}
nrun += nt;
/* Do only the condition estimate if INFO is not 0. */
if (trfcon) {
rcondc = 0.f;
goto L140;
}
i__3 = *nns;
for (irhs = 1; irhs <= i__3; ++irhs) {
nrhs = nsval[irhs];
/* + TEST 3 */
/* Solve and compute residual for A * X = B. */
s_copy(srnamc_1.srnamt, "SLARHS", (ftnlen)6, (ftnlen)6);
slarhs_(path, xtype, uplo, " ", &n, &n, &kl, &ku, &nrhs, &
a[1], &lda, &xact[1], &lda, &b[1], &lda, iseed, &
info);
slacpy_("Full", &n, &nrhs, &b[1], &lda, &x[1], &lda);
s_copy(srnamc_1.srnamt, "SSPTRS", (ftnlen)6, (ftnlen)6);
ssptrs_(uplo, &n, &nrhs, &afac[1], &iwork[1], &x[1], &lda,
&info);
/* Check error code from SSPTRS. */
if (info != 0) {
alaerh_(path, "SSPTRS", &info, &c__0, uplo, &n, &n, &
c_n1, &c_n1, &nrhs, &imat, &nfail, &nerrs,
nout);
}
slacpy_("Full", &n, &nrhs, &b[1], &lda, &work[1], &lda);
sppt02_(uplo, &n, &nrhs, &a[1], &x[1], &lda, &work[1], &
lda, &rwork[1], &result[2]);
/* + TEST 4 */
/* Check solution from generated exact solution. */
sget04_(&n, &nrhs, &x[1], &lda, &xact[1], &lda, &rcondc, &
result[3]);
/* + TESTS 5, 6, and 7 */
/* Use iterative refinement to improve the solution. */
s_copy(srnamc_1.srnamt, "SSPRFS", (ftnlen)6, (ftnlen)6);
ssprfs_(uplo, &n, &nrhs, &a[1], &afac[1], &iwork[1], &b[1]
, &lda, &x[1], &lda, &rwork[1], &rwork[nrhs + 1],
&work[1], &iwork[n + 1], &info);
/* Check error code from SSPRFS. */
if (info != 0) {
alaerh_(path, "SSPRFS", &info, &c__0, uplo, &n, &n, &
c_n1, &c_n1, &nrhs, &imat, &nfail, &nerrs,
nout);
}
sget04_(&n, &nrhs, &x[1], &lda, &xact[1], &lda, &rcondc, &
result[4]);
sppt05_(uplo, &n, &nrhs, &a[1], &b[1], &lda, &x[1], &lda,
&xact[1], &lda, &rwork[1], &rwork[nrhs + 1], &
result[5]);
/* Print information about the tests that did not pass */
/* the threshold. */
for (k = 3; k <= 7; ++k) {
if (result[k - 1] >= *thresh) {
if (nfail == 0 && nerrs == 0) {
alahd_(nout, path);
}
io___41.ciunit = *nout;
s_wsfe(&io___41);
do_fio(&c__1, uplo, (ftnlen)1);
do_fio(&c__1, (char *)&n, (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(real));
e_wsfe();
++nfail;
}
/* L120: */
}
nrun += 5;
/* L130: */
}
/* + TEST 8 */
/* Get an estimate of RCOND = 1/CNDNUM. */
L140:
anorm = slansp_("1", uplo, &n, &a[1], &rwork[1]);
s_copy(srnamc_1.srnamt, "SSPCON", (ftnlen)6, (ftnlen)6);
sspcon_(uplo, &n, &afac[1], &iwork[1], &anorm, &rcond, &work[
1], &iwork[n + 1], &info);
/* Check error code from SSPCON. */
if (info != 0) {
alaerh_(path, "SSPCON", &info, &c__0, uplo, &n, &n, &c_n1,
&c_n1, &c_n1, &imat, &nfail, &nerrs, nout);
}
result[7] = sget06_(&rcond, &rcondc);
/* Print the test ratio if it is .GE. THRESH. */
if (result[7] >= *thresh) {
if (nfail == 0 && nerrs == 0) {
alahd_(nout, path);
}
io___43.ciunit = *nout;
s_wsfe(&io___43);
do_fio(&c__1, uplo, (ftnlen)1);
do_fio(&c__1, (char *)&n, (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(real));
e_wsfe();
++nfail;
}
++nrun;
L150:
;
}
L160:
;
}
/* L170: */
}
/* Print a summary of the results. */
alasum_(path, nout, &nfail, &nrun, &nerrs);
return 0;
/* End of SCHKSP */
} /* schksp_ */
int sspsvx_(char *fact, char *uplo, int *n, int *
nrhs, float *ap, float *afp, int *ipiv, float *b, int *ldb, float
*x, int *ldx, float *rcond, float *ferr, float *berr, float *work,
int *iwork, int *info)
{
/* System generated locals */
int b_dim1, b_offset, x_dim1, x_offset, i__1;
/* Local variables */
extern int lsame_(char *, char *);
float anorm;
extern int scopy_(int *, float *, int *, float *,
int *);
extern double slamch_(char *);
int nofact;
extern int xerbla_(char *, int *), slacpy_(
char *, int *, int *, float *, int *, float *, int *
);
extern double slansp_(char *, char *, int *, float *, float *);
extern int sspcon_(char *, int *, float *, int *,
float *, float *, float *, int *, int *), ssprfs_(
char *, int *, int *, float *, float *, int *, float *,
int *, float *, int *, float *, float *, float *, int *,
int *), ssptrf_(char *, int *, float *, int *,
int *), ssptrs_(char *, int *, int *, float *,
int *, float *, int *, int *);
/* -- LAPACK driver routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* SSPSVX uses the diagonal pivoting factorization A = U*D*U**T or */
/* A = L*D*L**T to compute the solution to a float system of linear */
/* equations A * X = B, where A is an N-by-N symmetric matrix stored */
/* in packed format 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 = 'N', the diagonal pivoting method is used to factor A as */
/* A = U * D * U**T, if UPLO = 'U', or */
/* A = L * D * L**T, if UPLO = 'L', */
/* where U (or L) is a product of permutation and unit upper (lower) */
/* triangular matrices and D is symmetric and block diagonal with */
/* 1-by-1 and 2-by-2 diagonal blocks. */
/* 2. If some D(i,i)=0, so that D is exactly singular, 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. */
/* 3. The system of equations is solved for X using the factored form */
/* of A. */
/* 4. Iterative refinement is applied to improve the computed solution */
/* matrix and calculate error bounds and backward error estimates */
/* for it. */
/* Arguments */
/* ========= */
/* FACT (input) CHARACTER*1 */
/* Specifies whether or not the factored form of A has been */
/* supplied on entry. */
/* = 'F': On entry, AFP and IPIV contain the factored form of */
/* A. AP, AFP and IPIV will not be modified. */
/* = 'N': The matrix A will be copied to AFP 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. */
/* NRHS (input) INTEGER */
/* The number of right hand sides, i.e., the number of columns */
/* of the matrices B and X. NRHS >= 0. */
/* AP (input) REAL array, dimension (N*(N+1)/2) */
/* The upper or lower triangle of the symmetric matrix A, packed */
/* columnwise in a linear array. The j-th column of A is stored */
/* in the array AP as follows: */
/* if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j; */
/* if UPLO = 'L', AP(i + (j-1)*(2*n-j)/2) = A(i,j) for j<=i<=n. */
/* See below for further details. */
/* AFP (input or output) REAL array, dimension */
/* (N*(N+1)/2) */
/* If FACT = 'F', then AFP is an input argument and on entry */
/* contains the block diagonal matrix D and the multipliers used */
/* to obtain the factor U or L from the factorization */
/* A = U*D*U**T or A = L*D*L**T as computed by SSPTRF, stored as */
/* a packed triangular matrix in the same storage format as A. */
/* If FACT = 'N', then AFP is an output argument and on exit */
/* contains the block diagonal matrix D and the multipliers used */
/* to obtain the factor U or L from the factorization */
/* A = U*D*U**T or A = L*D*L**T as computed by SSPTRF, stored as */
/* a packed triangular matrix in the same storage format as A. */
/* IPIV (input or output) INTEGER array, dimension (N) */
/* If FACT = 'F', then IPIV is an input argument and on entry */
/* contains details of the interchanges and the block structure */
/* of D, as determined by SSPTRF. */
/* If IPIV(k) > 0, then rows and columns k and IPIV(k) were */
/* interchanged and D(k,k) is a 1-by-1 diagonal block. */
/* If UPLO = 'U' and IPIV(k) = IPIV(k-1) < 0, then rows and */
/* columns k-1 and -IPIV(k) were interchanged and D(k-1:k,k-1:k) */
/* is a 2-by-2 diagonal block. If UPLO = 'L' and IPIV(k) = */
/* IPIV(k+1) < 0, then rows and columns k+1 and -IPIV(k) were */
/* interchanged and D(k:k+1,k:k+1) is a 2-by-2 diagonal block. */
/* If FACT = 'N', then IPIV is an output argument and on exit */
/* contains details of the interchanges and the block structure */
/* of D, as determined by SSPTRF. */
/* B (input) REAL array, dimension (LDB,NRHS) */
/* The N-by-NRHS right hand side matrix B. */
/* LDB (input) INTEGER */
/* The leading dimension of the array B. LDB >= MAX(1,N). */
/* X (output) REAL array, dimension (LDX,NRHS) */
/* If INFO = 0 or INFO = N+1, the N-by-NRHS solution matrix 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. 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) REAL array, dimension (3*N) */
/* IWORK (workspace) INTEGER 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: D(i,i) is exactly zero. The factorization */
/* has been completed but the factor D is exactly */
/* singular, so the solution and error bounds could */
/* not be computed. RCOND = 0 is returned. */
/* = N+1: D 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 packed storage scheme is illustrated by the following example */
/* when N = 4, UPLO = 'U': */
/* Two-dimensional storage of the symmetric matrix A: */
/* a11 a12 a13 a14 */
/* a22 a23 a24 */
/* a33 a34 (aij = aji) */
/* a44 */
/* Packed storage of the upper triangle of A: */
/* AP = [ a11, a12, a22, a13, a23, a33, a14, a24, a34, a44 ] */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Test the input parameters. */
/* Parameter adjustments */
--ap;
--afp;
--ipiv;
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;
--iwork;
/* Function Body */
*info = 0;
nofact = lsame_(fact, "N");
if (! nofact && ! lsame_(fact, "F")) {
*info = -1;
} else if (! lsame_(uplo, "U") && ! lsame_(uplo,
"L")) {
*info = -2;
} else if (*n < 0) {
*info = -3;
} else if (*nrhs < 0) {
*info = -4;
} else if (*ldb < MAX(1,*n)) {
*info = -9;
} else if (*ldx < MAX(1,*n)) {
*info = -11;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("SSPSVX", &i__1);
return 0;
}
if (nofact) {
/* Compute the factorization A = U*D*U' or A = L*D*L'. */
i__1 = *n * (*n + 1) / 2;
scopy_(&i__1, &ap[1], &c__1, &afp[1], &c__1);
ssptrf_(uplo, n, &afp[1], &ipiv[1], info);
/* Return if INFO is non-zero. */
if (*info > 0) {
*rcond = 0.f;
return 0;
}
}
/* Compute the norm of the matrix A. */
anorm = slansp_("I", uplo, n, &ap[1], &work[1]);
/* Compute the reciprocal of the condition number of A. */
sspcon_(uplo, n, &afp[1], &ipiv[1], &anorm, rcond, &work[1], &iwork[1],
info);
/* Compute the solution vectors X. */
slacpy_("Full", n, nrhs, &b[b_offset], ldb, &x[x_offset], ldx);
ssptrs_(uplo, n, nrhs, &afp[1], &ipiv[1], &x[x_offset], ldx, info);
/* Use iterative refinement to improve the computed solutions and */
/* compute error bounds and backward error estimates for them. */
ssprfs_(uplo, n, nrhs, &ap[1], &afp[1], &ipiv[1], &b[b_offset], ldb, &x[
x_offset], ldx, &ferr[1], &berr[1], &work[1], &iwork[1], info);
/* Set INFO = N+1 if the matrix is singular to working precision. */
if (*rcond < slamch_("Epsilon")) {
*info = *n + 1;
}
return 0;
/* End of SSPSVX */
} /* sspsvx_ */
/* Subroutine */ int ssprfs_(char *uplo, integer *n, integer *nrhs, real *ap,
real *afp, integer *ipiv, real *b, integer *ldb, real *x, integer *
ldx, real *ferr, real *berr, real *work, integer *iwork, integer *
info)
{
/* System generated locals */
integer b_dim1, b_offset, x_dim1, x_offset, i__1, i__2, i__3;
real r__1, r__2, r__3;
/* Local variables */
integer i__, j, k;
real s;
integer ik, kk;
real xk;
integer nz;
real eps;
integer kase;
real safe1, safe2;
extern logical lsame_(char *, char *);
integer isave[3], count;
logical upper;
extern /* Subroutine */ int scopy_(integer *, real *, integer *, real *,
integer *), saxpy_(integer *, real *, real *, integer *, real *,
integer *), sspmv_(char *, integer *, real *, real *, real *,
integer *, real *, real *, integer *), slacn2_(integer *,
real *, real *, integer *, real *, integer *, integer *);
extern doublereal slamch_(char *);
real safmin;
extern /* Subroutine */ int xerbla_(char *, integer *);
real lstres;
extern /* Subroutine */ int ssptrs_(char *, integer *, integer *, real *,
integer *, real *, integer *, integer *);
/* -- LAPACK routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* Modified to call SLACN2 in place of SLACON, 5 Feb 03, SJH. */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* SSPRFS improves the computed solution to a system of linear */
/* equations when the coefficient matrix is symmetric indefinite */
/* and packed, and provides error bounds and backward error estimates */
/* for the solution. */
/* Arguments */
/* ========= */
/* UPLO (input) CHARACTER*1 */
/* = 'U': Upper triangle of A is stored; */
/* = 'L': Lower triangle of A is stored. */
/* N (input) INTEGER */
/* The order of the matrix A. N >= 0. */
/* NRHS (input) INTEGER */
/* The number of right hand sides, i.e., the number of columns */
/* of the matrices B and X. NRHS >= 0. */
/* AP (input) REAL array, dimension (N*(N+1)/2) */
/* The upper or lower triangle of the symmetric matrix A, packed */
/* columnwise in a linear array. The j-th column of A is stored */
/* in the array AP as follows: */
/* if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j; */
/* if UPLO = 'L', AP(i + (j-1)*(2*n-j)/2) = A(i,j) for j<=i<=n. */
/* AFP (input) REAL array, dimension (N*(N+1)/2) */
/* The factored form of the matrix A. AFP contains the block */
/* diagonal matrix D and the multipliers used to obtain the */
/* factor U or L from the factorization A = U*D*U**T or */
/* A = L*D*L**T as computed by SSPTRF, stored as a packed */
/* triangular matrix. */
/* IPIV (input) INTEGER array, dimension (N) */
/* Details of the interchanges and the block structure of D */
/* as determined by SSPTRF. */
/* B (input) REAL 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/output) REAL array, dimension (LDX,NRHS) */
/* On entry, the solution matrix X, as computed by SSPTRS. */
/* On exit, the improved solution matrix X. */
/* LDX (input) INTEGER */
/* The leading dimension of the array X. LDX >= max(1,N). */
/* 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) REAL array, dimension (3*N) */
/* IWORK (workspace) INTEGER array, dimension (N) */
/* INFO (output) INTEGER */
/* = 0: successful exit */
/* < 0: if INFO = -i, the i-th argument had an illegal value */
/* Internal Parameters */
/* =================== */
/* ITMAX is the maximum number of steps of iterative refinement. */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. Local Arrays .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Test the input parameters. */
/* Parameter adjustments */
--ap;
--afp;
--ipiv;
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;
--iwork;
/* Function Body */
*info = 0;
upper = lsame_(uplo, "U");
if (! upper && ! lsame_(uplo, "L")) {
*info = -1;
} else if (*n < 0) {
*info = -2;
} else if (*nrhs < 0) {
*info = -3;
} else if (*ldb < max(1,*n)) {
*info = -8;
} else if (*ldx < max(1,*n)) {
*info = -10;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("SSPRFS", &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.f;
berr[j] = 0.f;
/* L10: */
}
return 0;
}
/* NZ = maximum number of nonzero elements in each row of A, plus 1 */
nz = *n + 1;
eps = slamch_("Epsilon");
safmin = slamch_("Safe minimum");
safe1 = nz * safmin;
safe2 = safe1 / eps;
/* Do for each right hand side */
i__1 = *nrhs;
for (j = 1; j <= i__1; ++j) {
count = 1;
lstres = 3.f;
L20:
/* Loop until stopping criterion is satisfied. */
/* Compute residual R = B - A * X */
scopy_(n, &b[j * b_dim1 + 1], &c__1, &work[*n + 1], &c__1);
sspmv_(uplo, n, &c_b12, &ap[1], &x[j * x_dim1 + 1], &c__1, &c_b14, &
work[*n + 1], &c__1);
/* Compute componentwise relative backward error from formula */
/* max(i) ( abs(R(i)) / ( abs(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__) {
work[i__] = (r__1 = b[i__ + j * b_dim1], dabs(r__1));
/* L30: */
}
/* Compute abs(A)*abs(X) + abs(B). */
kk = 1;
if (upper) {
i__2 = *n;
for (k = 1; k <= i__2; ++k) {
s = 0.f;
xk = (r__1 = x[k + j * x_dim1], dabs(r__1));
ik = kk;
i__3 = k - 1;
for (i__ = 1; i__ <= i__3; ++i__) {
work[i__] += (r__1 = ap[ik], dabs(r__1)) * xk;
s += (r__1 = ap[ik], dabs(r__1)) * (r__2 = x[i__ + j *
x_dim1], dabs(r__2));
++ik;
/* L40: */
}
work[k] = work[k] + (r__1 = ap[kk + k - 1], dabs(r__1)) * xk
+ s;
kk += k;
/* L50: */
}
} else {
i__2 = *n;
for (k = 1; k <= i__2; ++k) {
s = 0.f;
xk = (r__1 = x[k + j * x_dim1], dabs(r__1));
work[k] += (r__1 = ap[kk], dabs(r__1)) * xk;
ik = kk + 1;
i__3 = *n;
for (i__ = k + 1; i__ <= i__3; ++i__) {
work[i__] += (r__1 = ap[ik], dabs(r__1)) * xk;
s += (r__1 = ap[ik], dabs(r__1)) * (r__2 = x[i__ + j *
x_dim1], dabs(r__2));
++ik;
/* L60: */
}
work[k] += s;
kk += *n - k + 1;
/* L70: */
}
}
s = 0.f;
i__2 = *n;
for (i__ = 1; i__ <= i__2; ++i__) {
if (work[i__] > safe2) {
/* Computing MAX */
r__2 = s, r__3 = (r__1 = work[*n + i__], dabs(r__1)) / work[
i__];
s = dmax(r__2,r__3);
} else {
/* Computing MAX */
r__2 = s, r__3 = ((r__1 = work[*n + i__], dabs(r__1)) + safe1)
/ (work[i__] + safe1);
s = dmax(r__2,r__3);
}
/* L80: */
}
berr[j] = s;
/* Test stopping criterion. Continue iterating if */
/* 1) The residual BERR(J) is larger than machine epsilon, and */
/* 2) BERR(J) decreased by at least a factor of 2 during the */
/* last iteration, and */
/* 3) At most ITMAX iterations tried. */
if (berr[j] > eps && berr[j] * 2.f <= lstres && count <= 5) {
/* Update solution and try again. */
ssptrs_(uplo, n, &c__1, &afp[1], &ipiv[1], &work[*n + 1], n, info);
saxpy_(n, &c_b14, &work[*n + 1], &c__1, &x[j * x_dim1 + 1], &c__1)
;
lstres = berr[j];
++count;
goto L20;
}
/* Bound error from formula */
/* norm(X - XTRUE) / norm(X) .le. FERR = */
/* norm( abs(inv(A))* */
/* ( abs(R) + NZ*EPS*( abs(A)*abs(X)+abs(B) ))) / norm(X) */
/* where */
/* norm(Z) is the magnitude of the largest component of Z */
/* inv(A) is the inverse of 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(A)*abs(X)+abs(B)) */
/* is incremented by SAFE1 if the i-th component of */
/* abs(A)*abs(X) + abs(B) is less than SAFE2. */
/* Use SLACN2 to estimate the infinity-norm of the matrix */
/* inv(A) * diag(W), */
/* where W = abs(R) + NZ*EPS*( abs(A)*abs(X)+abs(B) ))) */
i__2 = *n;
for (i__ = 1; i__ <= i__2; ++i__) {
if (work[i__] > safe2) {
work[i__] = (r__1 = work[*n + i__], dabs(r__1)) + nz * eps *
work[i__];
} else {
work[i__] = (r__1 = work[*n + i__], dabs(r__1)) + nz * eps *
work[i__] + safe1;
}
/* L90: */
}
kase = 0;
L100:
slacn2_(n, &work[(*n << 1) + 1], &work[*n + 1], &iwork[1], &ferr[j], &
kase, isave);
if (kase != 0) {
if (kase == 1) {
/* Multiply by diag(W)*inv(A'). */
ssptrs_(uplo, n, &c__1, &afp[1], &ipiv[1], &work[*n + 1], n,
info);
i__2 = *n;
for (i__ = 1; i__ <= i__2; ++i__) {
work[*n + i__] = work[i__] * work[*n + i__];
/* L110: */
}
} else if (kase == 2) {
/* Multiply by inv(A)*diag(W). */
i__2 = *n;
for (i__ = 1; i__ <= i__2; ++i__) {
work[*n + i__] = work[i__] * work[*n + i__];
/* L120: */
}
ssptrs_(uplo, n, &c__1, &afp[1], &ipiv[1], &work[*n + 1], n,
info);
}
goto L100;
}
/* Normalize error. */
lstres = 0.f;
i__2 = *n;
for (i__ = 1; i__ <= i__2; ++i__) {
/* Computing MAX */
r__2 = lstres, r__3 = (r__1 = x[i__ + j * x_dim1], dabs(r__1));
lstres = dmax(r__2,r__3);
/* L130: */
}
if (lstres != 0.f) {
ferr[j] /= lstres;
}
/* L140: */
}
return 0;
/* End of SSPRFS */
} /* ssprfs_ */
int sspsv_(char *uplo, int *n, int *nrhs, float *ap,
int *ipiv, float *b, int *ldb, int *info)
{
/* System generated locals */
int b_dim1, b_offset, i__1;
/* Local variables */
extern int lsame_(char *, char *);
extern int xerbla_(char *, int *), ssptrf_(
char *, int *, float *, int *, int *), ssptrs_(
char *, int *, int *, float *, int *, float *, int *
, int *);
/* -- LAPACK driver routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* SSPSV computes the solution to a float system of linear equations */
/* A * X = B, */
/* where A is an N-by-N symmetric matrix stored in packed format and X */
/* and B are N-by-NRHS matrices. */
/* The diagonal pivoting method is used to factor A as */
/* A = U * D * U**T, if UPLO = 'U', or */
/* A = L * D * L**T, if UPLO = 'L', */
/* where U (or L) is a product of permutation and unit upper (lower) */
/* triangular matrices, D is symmetric and block diagonal with 1-by-1 */
/* and 2-by-2 diagonal blocks. The factored form of A is then used to */
/* solve the system of equations A * X = B. */
/* Arguments */
/* ========= */
/* 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. */
/* NRHS (input) INTEGER */
/* The number of right hand sides, i.e., the number of columns */
/* of the matrix B. NRHS >= 0. */
/* AP (input/output) REAL array, dimension (N*(N+1)/2) */
/* On entry, the upper or lower triangle of the symmetric matrix */
/* A, packed columnwise in a linear array. The j-th column of A */
/* is stored in the array AP as follows: */
/* if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j; */
/* if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n. */
/* See below for further details. */
/* On exit, the block diagonal matrix D and the multipliers used */
/* to obtain the factor U or L from the factorization */
/* A = U*D*U**T or A = L*D*L**T as computed by SSPTRF, stored as */
/* a packed triangular matrix in the same storage format as A. */
/* IPIV (output) INTEGER array, dimension (N) */
/* Details of the interchanges and the block structure of D, as */
/* determined by SSPTRF. If IPIV(k) > 0, then rows and columns */
/* k and IPIV(k) were interchanged, and D(k,k) is a 1-by-1 */
/* diagonal block. If UPLO = 'U' and IPIV(k) = IPIV(k-1) < 0, */
/* then rows and columns k-1 and -IPIV(k) were interchanged and */
/* D(k-1:k,k-1:k) is a 2-by-2 diagonal block. If UPLO = 'L' and */
/* IPIV(k) = IPIV(k+1) < 0, then rows and columns k+1 and */
/* -IPIV(k) were interchanged and D(k:k+1,k:k+1) is a 2-by-2 */
/* diagonal block. */
/* B (input/output) REAL array, dimension (LDB,NRHS) */
/* On entry, the N-by-NRHS right hand side matrix B. */
/* On exit, if INFO = 0, the N-by-NRHS 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, D(i,i) is exactly zero. The factorization */
/* has been completed, but the block diagonal matrix D is */
/* exactly singular, so the solution could not be */
/* computed. */
/* Further Details */
/* =============== */
/* The packed storage scheme is illustrated by the following example */
/* when N = 4, UPLO = 'U': */
/* Two-dimensional storage of the symmetric matrix A: */
/* a11 a12 a13 a14 */
/* a22 a23 a24 */
/* a33 a34 (aij = aji) */
/* a44 */
/* Packed storage of the upper triangle of A: */
/* AP = [ a11, a12, a22, a13, a23, a33, a14, a24, a34, a44 ] */
/* ===================================================================== */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Test the input parameters. */
/* Parameter adjustments */
--ap;
--ipiv;
b_dim1 = *ldb;
b_offset = 1 + b_dim1;
b -= b_offset;
/* Function Body */
*info = 0;
if (! lsame_(uplo, "U") && ! lsame_(uplo, "L")) {
*info = -1;
} else if (*n < 0) {
*info = -2;
} else if (*nrhs < 0) {
*info = -3;
} else if (*ldb < MAX(1,*n)) {
*info = -7;
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("SSPSV ", &i__1);
return 0;
}
/* Compute the factorization A = U*D*U' or A = L*D*L'. */
ssptrf_(uplo, n, &ap[1], &ipiv[1], info);
if (*info == 0) {
/* Solve the system A*X = B, overwriting B with X. */
ssptrs_(uplo, n, nrhs, &ap[1], &ipiv[1], &b[b_offset], ldb, info);
}
return 0;
/* End of SSPSV */
} /* sspsv_ */
