/* Subroutine */ int zspt01_(char *uplo, integer *n, doublecomplex *a,
doublecomplex *afac, integer *ipiv, doublecomplex *c__, integer *ldc,
doublereal *rwork, doublereal *resid)
{
/* System generated locals */
integer c_dim1, c_offset, i__1, i__2, i__3, i__4, i__5;
doublecomplex z__1;
/* Local variables */
static integer info, i__, j;
extern logical lsame_(char *, char *);
static doublereal anorm;
static integer jc;
extern doublereal dlamch_(char *);
extern /* Subroutine */ int zlaset_(char *, integer *, integer *,
doublecomplex *, doublecomplex *, doublecomplex *, integer *);
extern doublereal zlansp_(char *, char *, integer *, doublecomplex *,
doublereal *);
extern /* Subroutine */ int zlavsp_(char *, char *, char *, integer *,
integer *, doublecomplex *, integer *, doublecomplex *, integer *,
integer *);
extern doublereal zlansy_(char *, char *, integer *, doublecomplex *,
integer *, doublereal *);
static doublereal eps;
#define c___subscr(a_1,a_2) (a_2)*c_dim1 + a_1
#define c___ref(a_1,a_2) c__[c___subscr(a_1,a_2)]
/* -- LAPACK test routine (version 3.0) --
Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
Courant Institute, Argonne National Lab, and Rice University
September 30, 1994
Purpose
=======
ZSPT01 reconstructs a symmetric indefinite packed matrix A from its
diagonal pivoting factorization A = U*D*U' or A = L*D*L' and computes
the residual
norm( C - A ) / ( N * norm(A) * EPS ),
where C is the reconstructed matrix and EPS is the machine epsilon.
Arguments
==========
UPLO (input) CHARACTER*1
Specifies whether the upper or lower triangular part of the
Hermitian matrix A is stored:
= 'U': Upper triangular
= 'L': Lower triangular
N (input) INTEGER
The order of the matrix A. N >= 0.
A (input) COMPLEX*16 array, dimension (N*(N+1)/2)
The original symmetric matrix A, stored as a packed
triangular matrix.
AFAC (input) COMPLEX*16 array, dimension (N*(N+1)/2)
The factored form of the matrix A, stored as a packed
triangular matrix. AFAC contains the block diagonal matrix D
and the multipliers used to obtain the factor L or U from the
L*D*L' or U*D*U' factorization as computed by ZSPTRF.
IPIV (input) INTEGER array, dimension (N)
The pivot indices from ZSPTRF.
C (workspace) COMPLEX*16 array, dimension (LDC,N)
LDC (integer) INTEGER
The leading dimension of the array C. LDC >= max(1,N).
RWORK (workspace) DOUBLE PRECISION array, dimension (N)
RESID (output) DOUBLE PRECISION
If UPLO = 'L', norm(L*D*L' - A) / ( N * norm(A) * EPS )
If UPLO = 'U', norm(U*D*U' - A) / ( N * norm(A) * EPS )
=====================================================================
Quick exit if N = 0.
Parameter adjustments */
--a;
--afac;
--ipiv;
c_dim1 = *ldc;
c_offset = 1 + c_dim1 * 1;
c__ -= c_offset;
--rwork;
/* Function Body */
if (*n <= 0) {
*resid = 0.;
return 0;
}
/* Determine EPS and the norm of A. */
eps = dlamch_("Epsilon");
anorm = zlansp_("1", uplo, n, &a[1], &rwork[1]);
/* Initialize C to the identity matrix. */
zlaset_("Full", n, n, &c_b1, &c_b2, &c__[c_offset], ldc);
/* Call ZLAVSP to form the product D * U' (or D * L' ). */
zlavsp_(uplo, "Transpose", "Non-unit", n, n, &afac[1], &ipiv[1], &c__[
c_offset], ldc, &info);
/* Call ZLAVSP again to multiply by U ( or L ). */
zlavsp_(uplo, "No transpose", "Unit", n, n, &afac[1], &ipiv[1], &c__[
c_offset], ldc, &info);
/* Compute the difference C - A . */
if (lsame_(uplo, "U")) {
jc = 0;
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = j;
for (i__ = 1; i__ <= i__2; ++i__) {
i__3 = c___subscr(i__, j);
i__4 = c___subscr(i__, j);
i__5 = jc + i__;
z__1.r = c__[i__4].r - a[i__5].r, z__1.i = c__[i__4].i - a[
i__5].i;
c__[i__3].r = z__1.r, c__[i__3].i = z__1.i;
/* L10: */
}
jc += j;
/* L20: */
}
} else {
jc = 1;
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = *n;
for (i__ = j; i__ <= i__2; ++i__) {
i__3 = c___subscr(i__, j);
i__4 = c___subscr(i__, j);
i__5 = jc + i__ - j;
z__1.r = c__[i__4].r - a[i__5].r, z__1.i = c__[i__4].i - a[
i__5].i;
c__[i__3].r = z__1.r, c__[i__3].i = z__1.i;
/* L30: */
}
jc = jc + *n - j + 1;
/* L40: */
}
}
/* Compute norm( C - A ) / ( N * norm(A) * EPS ) */
*resid = zlansy_("1", uplo, n, &c__[c_offset], ldc, &rwork[1]);
if (anorm <= 0.) {
if (*resid != 0.) {
*resid = 1. / eps;
}
} else {
*resid = *resid / (doublereal) (*n) / anorm / eps;
}
return 0;
/* End of ZSPT01 */
} /* zspt01_ */
/* Subroutine */ int zspt01_(char *uplo, integer *n, doublecomplex *a,
doublecomplex *afac, integer *ipiv, doublecomplex *c__, integer *ldc,
doublereal *rwork, doublereal *resid)
{
/* System generated locals */
integer c_dim1, c_offset, i__1, i__2, i__3, i__4, i__5;
doublecomplex z__1;
/* Local variables */
integer i__, j, jc;
doublereal eps;
integer info;
doublereal anorm;
/* -- LAPACK test routine (version 3.1) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* ZSPT01 reconstructs a symmetric indefinite packed matrix A from its */
/* diagonal pivoting factorization A = U*D*U' or A = L*D*L' and computes */
/* the residual */
/* norm( C - A ) / ( N * norm(A) * EPS ), */
/* where C is the reconstructed matrix and EPS is the machine epsilon. */
/* Arguments */
/* ========== */
/* UPLO (input) CHARACTER*1 */
/* Specifies whether the upper or lower triangular part of the */
/* Hermitian matrix A is stored: */
/* = 'U': Upper triangular */
/* = 'L': Lower triangular */
/* N (input) INTEGER */
/* The order of the matrix A. N >= 0. */
/* A (input) COMPLEX*16 array, dimension (N*(N+1)/2) */
/* The original symmetric matrix A, stored as a packed */
/* triangular matrix. */
/* AFAC (input) COMPLEX*16 array, dimension (N*(N+1)/2) */
/* The factored form of the matrix A, stored as a packed */
/* triangular matrix. AFAC contains the block diagonal matrix D */
/* and the multipliers used to obtain the factor L or U from the */
/* L*D*L' or U*D*U' factorization as computed by ZSPTRF. */
/* IPIV (input) INTEGER array, dimension (N) */
/* The pivot indices from ZSPTRF. */
/* C (workspace) COMPLEX*16 array, dimension (LDC,N) */
/* LDC (integer) INTEGER */
/* The leading dimension of the array C. LDC >= max(1,N). */
/* RWORK (workspace) DOUBLE PRECISION array, dimension (N) */
/* RESID (output) DOUBLE PRECISION */
/* If UPLO = 'L', norm(L*D*L' - A) / ( N * norm(A) * EPS ) */
/* If UPLO = 'U', norm(U*D*U' - A) / ( N * norm(A) * EPS ) */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Quick exit if N = 0. */
/* Parameter adjustments */
--a;
--afac;
--ipiv;
c_dim1 = *ldc;
c_offset = 1 + c_dim1;
c__ -= c_offset;
--rwork;
/* Function Body */
if (*n <= 0) {
*resid = 0.;
return 0;
}
/* Determine EPS and the norm of A. */
eps = dlamch_("Epsilon");
anorm = zlansp_("1", uplo, n, &a[1], &rwork[1]);
/* Initialize C to the identity matrix. */
zlaset_("Full", n, n, &c_b1, &c_b2, &c__[c_offset], ldc);
/* Call ZLAVSP to form the product D * U' (or D * L' ). */
zlavsp_(uplo, "Transpose", "Non-unit", n, n, &afac[1], &ipiv[1], &c__[
c_offset], ldc, &info);
/* Call ZLAVSP again to multiply by U ( or L ). */
zlavsp_(uplo, "No transpose", "Unit", n, n, &afac[1], &ipiv[1], &c__[
c_offset], ldc, &info);
/* Compute the difference C - A . */
if (lsame_(uplo, "U")) {
jc = 0;
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = j;
for (i__ = 1; i__ <= i__2; ++i__) {
i__3 = i__ + j * c_dim1;
i__4 = i__ + j * c_dim1;
i__5 = jc + i__;
z__1.r = c__[i__4].r - a[i__5].r, z__1.i = c__[i__4].i - a[
i__5].i;
c__[i__3].r = z__1.r, c__[i__3].i = z__1.i;
/* L10: */
}
jc += j;
/* L20: */
}
} else {
jc = 1;
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = *n;
for (i__ = j; i__ <= i__2; ++i__) {
i__3 = i__ + j * c_dim1;
i__4 = i__ + j * c_dim1;
i__5 = jc + i__ - j;
z__1.r = c__[i__4].r - a[i__5].r, z__1.i = c__[i__4].i - a[
i__5].i;
c__[i__3].r = z__1.r, c__[i__3].i = z__1.i;
/* L30: */
}
jc = jc + *n - j + 1;
/* L40: */
}
}
/* Compute norm( C - A ) / ( N * norm(A) * EPS ) */
*resid = zlansy_("1", uplo, n, &c__[c_offset], ldc, &rwork[1]);
if (anorm <= 0.) {
if (*resid != 0.) {
*resid = 1. / eps;
}
} else {
*resid = *resid / (doublereal) (*n) / anorm / eps;
}
return 0;
/* End of ZSPT01 */
} /* zspt01_ */
