Contents
ssytrs - solve a system of linear equations A*X = B with a
real symmetric matrix A using the factorization A = U*D*U**T
or A = L*D*L**T computed by SSYTRF
SUBROUTINE SSYTRS(UPLO, N, NRHS, A, LDA, IPIVOT, B, LDB, INFO)
CHARACTER * 1 UPLO
INTEGER N, NRHS, LDA, LDB, INFO
INTEGER IPIVOT(*)
REAL A(LDA,*), B(LDB,*)
SUBROUTINE SSYTRS_64(UPLO, N, NRHS, A, LDA, IPIVOT, B, LDB, INFO)
CHARACTER * 1 UPLO
INTEGER*8 N, NRHS, LDA, LDB, INFO
INTEGER*8 IPIVOT(*)
REAL A(LDA,*), B(LDB,*)
F95 INTERFACE
SUBROUTINE SYTRS(UPLO, N, NRHS, A, [LDA], IPIVOT, B, [LDB], [INFO])
CHARACTER(LEN=1) :: UPLO
INTEGER :: N, NRHS, LDA, LDB, INFO
INTEGER, DIMENSION(:) :: IPIVOT
REAL, DIMENSION(:,:) :: A, B
SUBROUTINE SYTRS_64(UPLO, N, NRHS, A, [LDA], IPIVOT, B, [LDB], [INFO])
CHARACTER(LEN=1) :: UPLO
INTEGER(8) :: N, NRHS, LDA, LDB, INFO
INTEGER(8), DIMENSION(:) :: IPIVOT
REAL, DIMENSION(:,:) :: A, B
C INTERFACE
#include <sunperf.h>
void ssytrs(char uplo, int n, int nrhs, float *a, int lda,
int *ipivot, float *b, int ldb, int *info);
void ssytrs_64(char uplo, long n, long nrhs, float *a, long
lda, long *ipivot, float *b, long ldb, long
*info);
ssytrs solves a system of linear equations A*X = B with a
real symmetric matrix A using the factorization A = U*D*U**T
or A = L*D*L**T computed by SSYTRF.
UPLO (input)
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) The order of the matrix A. N >= 0.
NRHS (input)
The number of right hand sides, i.e., the number
of columns of the matrix B. NRHS >= 0.
A (input) The block diagonal matrix D and the multipliers
used to obtain the factor U or L as computed by
SSYTRF.
LDA (input)
The leading dimension of the array A. LDA >=
max(1,N).
IPIVOT (input)
Details of the interchanges and the block struc-
ture of D as determined by SSYTRF.
B (input/output)
On entry, the right hand side matrix B. On exit,
the solution matrix X.
LDB (input)
The leading dimension of the array B. LDB >=
max(1,N).
INFO (output)
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an ille-
gal value