Performs matrix-matrix operations on triangular matrices.
BLAS Library (libblas.a)
SUBROUTINE STRMM(SIDE, UPLO, TRANSA, DIAG,
M, N, ALPHA, A, LDA, B, LDB)
CHARACTER*1 SIDE, UPLO, TRANSA, DIAG
INTEGER M, N, LDA, LDB
REAL ALPHA
REAL A(LDA,*), B(LDB,*)
SUBROUTINE DTRMM(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 CTRMM(SIDE, UPLO, TRANSA, DIAG,
M, N, ALPHA, A, LDA, B, LDB)
CHARACTER*1
SIDE,UPLO,TRANSA,DIAG
INTEGER M,N,LDA,LDB
COMPLEX ALPHA
COMPLEX A(LDA,*), B(LDB,*)
SUBROUTINE ZTRMM(SIDE, UPLO, TRANSA, DIAG,
M, N, ALPHA, A, LDA, B, LDB)
CHARACTER*1
SIDE,UPLO,TRANSA,DIAG
INTEGER M,N,LDA,LDB
COMPLEX*16 ALPHA
COMPLEX*16 A(LDA,*), B(LDB,*)
The STRMM, DTRMM, CTRMM, or ZTRMM subroutine performs one of the matrix-matrix operations:
B := alpha * op( A ) * B
OR
B := alpha * B * op( A )
where alpha is a scalar, B is an M by N matrix, A is a unit, or non-unit, upper or lower triangular matrix, and op( A ) is either op( A ) = A or op( A ) = A'.
Item | Description |
---|---|
SIDE | On entry, SIDE specifies whether op( A ) multiplies B
from the left or right as follows:
Unchanged on exit. |
UPLO | On entry, UPLO specifies whether the matrix A is
an upper or lower triangular matrix as follows:
Unchanged on exit. |
TRANSA | On entry, TRANSA specifies the form of op( A )
to be used in the matrix multiplication as follows:
Unchanged on exit. |
DIAG | On entry, DIAG specifies whether or not A is
unit triangular as follows:
Unchanged on exit. |
M | On entry, M specifies the number of rows of B; M must be at least 0; unchanged on exit. |
N | On entry, N specifies the number of columns of B; N must be at least 0; unchanged on exit. |
ALPHA | On entry, ALPHA specifies the scalar alpha. When alpha is 0 then A is not referenced and B need not be set before entry; unchanged on exit. |
A | An array of dimension ( LDA, k ), where k is M when SIDE = 'L' or 'l' and is N when SIDE = 'R' or 'r'; on entry with UPLO = 'U' or 'u', the leading 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 referenced; on entry with UPLO = 'L' or 'l', the leading 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 referenced. When DIAG = 'U' or 'u', the diagonal elements of A are not referenced either, but are assumed to be unity; unchanged on exit. |
LDA | On entry, LDA specifies the first dimension of A as declared in the calling (sub) program. When SIDE = 'L' or 'l' then LDA must be at least max( 1, M ), when SIDE = 'R' or 'r' then LDA must be at least max( 1, N ); unchanged on exit. |
B | An array of dimension ( LDB, N ); on entry, the leading M by N part of the array B must contain the matrix B, and on exit is overwritten by the transformed matrix. |
LDB | On entry, LDB specifies the first dimension of B as declared in the calling (sub) program; LDB must be at least max( 1, M ); unchanged on exit. |