Contents
dtrsm - solve one of the matrix equations op( A )*X =
alpha*B, or X*op( A ) = alpha*B
SUBROUTINE DTRSM(SIDE, UPLO, TRANSA, DIAG, M, N, ALPHA, A, LDA, B,
LDB)
CHARACTER * 1 SIDE, UPLO, TRANSA, DIAG
INTEGER M, N, LDA, LDB
DOUBLE PRECISION ALPHA
DOUBLE PRECISION A(LDA,*), B(LDB,*)
SUBROUTINE DTRSM_64(SIDE, UPLO, TRANSA, DIAG, M, N, ALPHA, A, LDA, B,
LDB)
CHARACTER * 1 SIDE, UPLO, TRANSA, DIAG
INTEGER*8 M, N, LDA, LDB
DOUBLE PRECISION ALPHA
DOUBLE PRECISION A(LDA,*), B(LDB,*)
F95 INTERFACE
SUBROUTINE TRSM(SIDE, UPLO, [TRANSA], DIAG, [M], [N], ALPHA, A, [LDA],
B, [LDB])
CHARACTER(LEN=1) :: SIDE, UPLO, TRANSA, DIAG
INTEGER :: M, N, LDA, LDB
REAL(8) :: ALPHA
REAL(8), DIMENSION(:,:) :: A, B
SUBROUTINE TRSM_64(SIDE, UPLO, [TRANSA], DIAG, [M], [N], ALPHA, A,
[LDA], B, [LDB])
CHARACTER(LEN=1) :: SIDE, UPLO, TRANSA, DIAG
INTEGER(8) :: M, N, LDA, LDB
REAL(8) :: ALPHA
REAL(8), DIMENSION(:,:) :: A, B
C INTERFACE
#include <sunperf.h>
void dtrsm(char side, char uplo, char transa, char diag, int
m, int n, double alpha, double *a, int lda, double
*b, int ldb);
void dtrsm_64(char side, char uplo, char transa, char diag,
long m, long n, double alpha, double *a, long lda,
double *b, long ldb);
dtrsm solves one of the matrix equations op( A )*X =
alpha*B, or X*op( A ) = alpha*B where alpha is a scalar, X
and B are m by n matrices, A is a unit, or non-unit, upper
or lower triangular matrix and op( A ) is one of
op( A ) = A or op( A ) = A'.
The matrix X is overwritten on B.
SIDE (input)
On entry, SIDE specifies whether op( A ) appears
on the left or right of X as follows:
SIDE = 'L' or 'l' op( A )*X = alpha*B.
SIDE = 'R' or 'r' X*op( A ) = alpha*B.
Unchanged on exit.
UPLO (input)
On entry, UPLO specifies whether the matrix A is
an upper or lower triangular matrix as follows:
UPLO = 'U' or 'u' A is an upper triangular
matrix.
UPLO = 'L' or 'l' A is a lower triangular
matrix.
Unchanged on exit.
TRANSA (input)
On entry, TRANSA specifies the form of op( A ) to
be used in the matrix multiplication as follows:
TRANSA = 'N' or 'n' op( A ) = A.
TRANSA = 'T' or 't' op( A ) = A'.
TRANSA = 'C' or 'c' op( A ) = A'.
Unchanged on exit.
TRANSA is defaulted to 'N' for F95 INTERFACE.
DIAG (input)
On entry, DIAG specifies whether or not A is unit
triangular as follows:
DIAG = 'U' or 'u' A is assumed to be unit tri-
angular.
DIAG = 'N' or 'n' A is not assumed to be unit
triangular.
Unchanged on exit.
M (input)
On entry, M specifies the number of rows of B. M
>= 0. Unchanged on exit.
N (input)
On entry, N specifies the number of columns of B.
N >= 0. Unchanged on exit.
ALPHA (input)
On entry, ALPHA specifies the scalar alpha. When
alpha is zero then A is not referenced and B
need not be set before entry. Unchanged on exit.
A (input)
DOUBLE PRECISION array of DIMENSION ( LDA, k ),
where k is m when SIDE = 'L' or 'l' and is n
when SIDE = 'R' or 'r'.
Before entry with UPLO = 'U' or 'u', the lead-
ing k by k upper triangular part of the array A
must contain the upper triangular matrix and the
strictly lower triangular part of A is not refer-
enced.
Before entry with UPLO = 'L' or 'l', the lead-
ing k by k lower triangular part of the array A
must contain the lower triangular matrix and the
strictly upper triangular part of A is not refer-
enced.
Note that when DIAG = 'U' or 'u', the diagonal
elements of A are not referenced either, but are
assumed to be one. Unchanged on exit.
LDA (input)
On entry, LDA specifies the first dimension of A
as declared in the calling (sub) program. When
SIDE = 'L' or 'l' then LDA >= max( 1, m ), when
SIDE = 'R' or 'r' then LDA >= max( 1, n ).
Unchanged on exit.
B (input/output)
DOUBLE PRECISION array of DIMENSION ( LDB, n ).
Before entry, the leading m by n part of the
array B must contain the right-hand side
matrix B, and on exit is overwritten by the
solution matrix X.
LDB (input)
On entry, LDB specifies the first dimension of B
as declared in the calling (sub) program. LDB
>= max( 1, m ). Unchanged on exit.