Visible to Intel only — GUID: GUID-0E088C97-E200-44A2-AA53-7DDBD070F061
Visible to Intel only — GUID: GUID-0E088C97-E200-44A2-AA53-7DDBD070F061
?trmm
Computes a matrix-matrix product where one input matrix is triangular.
Syntax
call strmm(side, uplo, transa, diag, m, n, alpha, a, lda, b, ldb)
call dtrmm(side, uplo, transa, diag, m, n, alpha, a, lda, b, ldb)
call ctrmm(side, uplo, transa, diag, m, n, alpha, a, lda, b, ldb)
call ztrmm(side, uplo, transa, diag, m, n, alpha, a, lda, b, ldb)
call trmm(a, b [,side] [, uplo] [,transa][,diag] [,alpha])
Include Files
- mkl.fi, blas.f90
Description
The ?trmm routines compute a scalar-matrix-matrix product with one triangular matrix . The operation is defined as
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
op(A) is one of op(A) = A, or op(A) = A', or op(A) = conjg(A').
Input Parameters
- side
-
CHARACTER*1. Specifies whether op(A) appears on the left or right of B in the operation:
if side = 'L' or 'l' , then B := alpha*op(A)*B;
if side = 'R' or 'r' , then B := alpha*B*op(A).
- uplo
-
CHARACTER*1. Specifies whether the matrix A is upper or lower triangular.
uplo = 'U' or 'u'if uplo = 'L' or 'l', then the matrix is low triangular.
- transa
-
CHARACTER*1. Specifies the form of op(A) used in the matrix multiplication:
if transa= 'N' or 'n' , then op(A) = A;
if transa= 'T' or 't' , then op(A) = A';
if transa= 'C' or 'c' , then op(A) = conjg(A').
- diag
-
CHARACTER*1. Specifies whether the matrix A is unit triangular:
if diag = 'U' or 'u' then the matrix is unit triangular;
if diag = 'N' or 'n' , then the matrix is not unit triangular.
- m
-
INTEGER. Specifies the number of rows of B. The value of m must be at least zero.
- n
-
INTEGER. Specifies the number of columns of B. The value of n must be at least zero.
- alpha
-
REAL for strmm
DOUBLE PRECISION for dtrmm
COMPLEX for ctrmm
DOUBLE COMPLEX for ztrmm
Specifies the scalar alpha.
When alpha is zero, then a is not referenced and b need not be set before entry.
- a
-
REAL for strmm
DOUBLE PRECISION for dtrmm
COMPLEX for ctrmm
DOUBLE COMPLEX for ztrmm
Array, size lda by k, where k is m when side = 'L'side or 'l' and is n when side = 'R' or 'r'. Before 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.
Before 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.
- lda
-
INTEGER. Specifies the leading dimension of a as declared in the calling (sub)program. Whenside = '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).
- b
-
REAL for strmm
DOUBLE PRECISION for dtrmm
COMPLEX for ctrmm
DOUBLE COMPLEX for ztrmm
Array, size ldb by n. Before entry, the leading m-by-n part of the array b must contain the matrix B.
- ldb
-
INTEGER. Specifies the leading dimension of b as declared in the calling (sub)program. ldb must be at least max(1, m)
Output Parameters
- b
-
Overwritten by the transformed matrix.
BLAS 95 Interface Notes
Routines in Fortran 95 interface have fewer arguments in the calling sequence than their FORTRAN 77 counterparts. For general conventions applied to skip redundant or reconstructible arguments, see BLAS 95 Interface Conventions.
Specific details for the routine trmm interface are the following:
- a
-
Holds the matrix A of size (k,k) where
k = m if side = 'L',
k = n otherwise.
- b
-
Holds the matrix B of size (m,n).
- side
-
Must be 'L' or 'R'. The default value is 'L'.
- uplo
-
Must be 'U' or 'L'. The default value is 'U'.
- transa
-
Must be 'N', 'C', or 'T'.
The default value is 'N'.
- diag
-
Must be 'N' or 'U'. The default value is 'N'.
- alpha
-
The default value is 1.