/*! \brief Let rhs[i] = sum of i-th row of A, so the solution vector is all 1's
*/
void
zFillRHS(trans_t trans, int nrhs, doublecomplex *x, int ldx,
SuperMatrix *A, SuperMatrix *B)
{
NCformat *Astore;
doublecomplex *Aval;
DNformat *Bstore;
doublecomplex *rhs;
doublecomplex one = {1.0, 0.0};
doublecomplex zero = {0.0, 0.0};
int ldc;
char transc[1];
Astore = A->Store;
Aval = (doublecomplex *) Astore->nzval;
Bstore = B->Store;
rhs = Bstore->nzval;
ldc = Bstore->lda;
if ( trans == NOTRANS ) *(unsigned char *)transc = 'N';
else *(unsigned char *)transc = 'T';
sp_zgemm(transc, "N", A->nrow, nrhs, A->ncol, one, A,
x, ldx, zero, rhs, ldc);
}
/*
* Let rhs[i] = sum of i-th row of A, so the solution vector is all 1's
*/
void
zFillRHS(char *trans, int nrhs, doublecomplex *x, int ldx,
SuperMatrix *A, SuperMatrix *B)
{
NCformat *Astore;
doublecomplex *Aval;
DNformat *Bstore;
doublecomplex *rhs;
doublecomplex one = {1.0, 0.0};
doublecomplex zero = {0.0, 0.0};
int ldc;
Astore = A->Store;
Aval = (doublecomplex *) Astore->nzval;
Bstore = B->Store;
rhs = Bstore->nzval;
ldc = Bstore->lda;
sp_zgemm(trans, "N", A->nrow, nrhs, A->ncol, one, A,
x, ldx, zero, rhs, ldc);
}
int zgst02(trans_t trans, int m, int n, int nrhs, SuperMatrix *A,
doublecomplex *x, int ldx, doublecomplex *b, int ldb, double *resid)
{
/*
Purpose
=======
ZGST02 computes the residual for a solution of a system of linear
equations A*x = b or A'*x = b:
RESID = norm(B - A*X) / ( norm(A) * norm(X) * EPS ),
where EPS is the machine epsilon.
Arguments
=========
TRANS (input) trans_t
Specifies the form of the system of equations:
= NOTRANS: A *x = b
= TRANS : A'*x = b, where A' is the transpose of A
= CONJ : A'*x = b, where A' is the transpose of A
M (input) INTEGER
The number of rows of the matrix A. M >= 0.
N (input) INTEGER
The number of columns of the matrix A. N >= 0.
NRHS (input) INTEGER
The number of columns of B, the matrix of right hand sides.
NRHS >= 0.
A (input) SuperMatrix*, dimension (LDA,N)
The original M x N sparse matrix A.
X (input) DOUBLE COMPLEX PRECISION array, dimension (LDX,NRHS)
The computed solution vectors for the system of linear
equations.
LDX (input) INTEGER
The leading dimension of the array X. If TRANS = NOTRANS,
LDX >= max(1,N); if TRANS = TRANS or CONJ, LDX >= max(1,M).
B (input/output) DOUBLE COMPLEX PRECISION array, dimension (LDB,NRHS)
On entry, the right hand side vectors for the system of
linear equations.
On exit, B is overwritten with the difference B - A*X.
LDB (input) INTEGER
The leading dimension of the array B. IF TRANS = NOTRANS,
LDB >= max(1,M); if TRANS = TRANS or CONJ, LDB >= max(1,N).
RESID (output) DOUBLE PRECISION
The maximum over the number of right hand sides of
norm(B - A*X) / ( norm(A) * norm(X) * EPS ).
=====================================================================
*/
/* Table of constant values */
doublecomplex alpha = {-1., 0.0};
doublecomplex beta = {1., 0.0};
int c__1 = 1;
/* System generated locals */
double d__1, d__2;
/* Local variables */
int j;
int n1, n2;
double anorm, bnorm;
double xnorm;
double eps;
char transc[1];
/* Function prototypes */
extern int lsame_(char *, char *);
extern double zlangs(char *, SuperMatrix *);
extern double dzasum_(int *, doublecomplex *, int *);
/* Function Body */
if ( m <= 0 || n <= 0 || nrhs == 0) {
*resid = 0.;
return 0;
}
if ( (trans == TRANS) || (trans == CONJ) ) {
n1 = n;
n2 = m;
*transc = 'T';
} else {
n1 = m;
n2 = n;
*transc = 'N';
}
/* Exit with RESID = 1/EPS if ANORM = 0. */
eps = dlamch_("Epsilon");
anorm = zlangs("1", A);
if (anorm <= 0.) {
*resid = 1. / eps;
return 0;
}
/* Compute B - A*X (or B - A'*X ) and store in B. */
sp_zgemm(transc, "N", n1, nrhs, n2, alpha, A, x, ldx, beta, b, ldb);
/* Compute the maximum over the number of right hand sides of
norm(B - A*X) / ( norm(A) * norm(X) * EPS ) . */
*resid = 0.;
for (j = 0; j < nrhs; ++j) {
bnorm = dzasum_(&n1, &b[j*ldb], &c__1);
xnorm = dzasum_(&n2, &x[j*ldx], &c__1);
if (xnorm <= 0.) {
*resid = 1. / eps;
} else {
/* Computing MAX */
d__1 = *resid, d__2 = bnorm / anorm / xnorm / eps;
*resid = SUPERLU_MAX(d__1, d__2);
}
}
return 0;
} /* zgst02 */
int pzgst02(trans_t trans, int m, int n, int nrhs, SuperMatrix *A,
doublecomplex *x, int ldx, doublecomplex *b, int ldb, double *resid)
{
/*
* -- SuperLU MT routine (version 2.0) --
* Lawrence Berkeley National Lab, Univ. of California Berkeley,
* and Xerox Palo Alto Research Center.
* September 10, 2007
*
* Purpose
* =======
*
* pzgst02() computes the residual for a solution of a system of linear
* equations A*x = b or A'*x = b:
* RESID = norm(B - A*X) / ( norm(A) * norm(X) * EPS ),
* where EPS is the machine epsilon.
*
* Arguments
* =========
*
* TRANS (input) trans_t
* Specifies the form of the system of equations:
* = NOTRANS: A *x = b
* = TRANS: A'*x = b, where A' is the transpose of A
* = CONJ: A'*x = b, where A' is the conjugate transpose of A
*
* M (input) INTEGER
*
* N (input) INTEGER
* The number of columns of the matrix A. N >= 0.
*
* NRHS (input) INTEGER
* The number of columns of B, the matrix of right hand sides.
* NRHS >= 0.
*
* A (input) SuperMatrix*, dimension (LDA,N)
* The original M x N sparse matrix A.
*
* X (input) DOUBLE PRECISION array, dimension (LDX,NRHS)
* The computed solution vectors for the system of linear
* equations.
*
* LDX (input) INTEGER
* The leading dimension of the array X. If TRANS = NOTRANS,
* LDX >= max(1,N); if TRANS = TRANS or CONJ, LDX >= max(1,M).
*
* B (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
* On entry, the right hand side vectors for the system of
* linear equations.
* On exit, B is overwritten with the difference B - A*X.
*
* LDB (input) INTEGER
* The leading dimension of the array B. IF TRANS = NOTRANS,
* LDB >= max(1,M); if TRANS = TRANS or CONJ, LDB >= max(1,N).
*
* RESID (output) DOUBLE PRECISION
* The maximum over the number of right hand sides of
*
* =====================================================================
*/
/* Table of constant values */
doublecomplex alpha = {-1., 0.0};
doublecomplex beta = {1., 0.0};
int c__1 = 1;
/* System generated locals */
double d__1, d__2;
/* Local variables */
int j;
int n1, n2;
double anorm, bnorm;
double xnorm;
double eps;
char transc[1];
/* Function prototypes */
extern int lsame_(char *, char *);
extern double zlangs(char *, SuperMatrix *);
extern double dzasum_(int *, doublecomplex *, int *);
extern double dlamch_(char *);
/* Function Body */
if ( m <= 0 || n <= 0 || nrhs == 0) {
*resid = 0.;
return 0;
}
if ( trans == TRANS || trans == CONJ ) {
n1 = n;
n2 = m;
} else {
n1 = m;
n2 = n;
}
/* Exit with RESID = 1/EPS if ANORM = 0. */
eps = dlamch_("Epsilon");
anorm = zlangs("1", A);
if (anorm <= 0.) {
*resid = 1. / eps;
return 0;
}
/* Compute B - A*X (or B - A'*X ) and store in B. */
if ( trans == NOTRANS ) *transc = 'N';
else if ( trans == TRANS ) *transc = 'T';
else if ( trans == CONJ ) *transc = 'C';
sp_zgemm(transc, n1, nrhs, n2, alpha, A, x, ldx, beta, b, ldb);
/*for (j = 0; j < m; ++j)
if ( b[j] > 0.001 ) { printf("b-Ax: %d, %f\n", j, b[j]); b[j] = 1.; }*/
/* Compute the maximum over the number of right hand sides of
norm(B - A*X) / ( norm(A) * norm(X) * EPS ) . */
*resid = 0.;
for (j = 0; j < nrhs; ++j) {
bnorm = dzasum_(&n1, &b[j*ldb], &c__1);
xnorm = dzasum_(&n2, &x[j*ldx], &c__1);
if (xnorm <= 0.) {
*resid = 1. / eps;
} else {
/* Computing MAX */
d__1 = *resid, d__2 = bnorm / anorm / xnorm / eps;
*resid = SUPERLU_MAX(d__1, d__2);
}
}
return 0;
} /* pzgst02 */
