NAME¶
ZTRMM - perform 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 one of op(
A ) = A or op( A ) = A' or op( A ) = conjg( A' )
SYNOPSIS¶
- 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, * )
PURPOSE¶
ZTRMM performs one of the matrix-matrix operations
PARAMETERS¶
- SIDE - CHARACTER*1.
- On entry, SIDE specifies whether op( A ) multiplies B from
the left or right as follows:
SIDE = 'L' or 'l' B := alpha*op( A )*B.
SIDE = 'R' or 'r' B := alpha*B*op( A ).
Unchanged on exit.
- UPLO - CHARACTER*1.
- 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 - CHARACTER*1. 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 ) = conjg( A' ).
Unchanged on exit.
- DIAG - CHARACTER*1.
- On entry, DIAG specifies whether or not A is unit
triangular as follows:
DIAG = 'U' or 'u' A is assumed to be unit triangular.
DIAG = 'N' or 'n' A is not assumed to be unit triangular.
Unchanged on exit.
- M - INTEGER.
- On entry, M specifies the number of rows of B. M must be at
least zero. Unchanged on exit.
- N - INTEGER.
- On entry, N specifies the number of columns of B. N must be
at least zero. Unchanged on exit.
- ALPHA - COMPLEX*16 .
- 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 - COMPLEX*16 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 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. Note that when DIAG = 'U' or 'u', the
diagonal elements of A are not referenced either, but are assumed to be
unity. Unchanged on exit.
- LDA - INTEGER.
- 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 - COMPLEX*16 array of DIMENSION ( LDB, n ).
- Before 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 - INTEGER.
- 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.
Level 3 Blas routine.
-- Written on 8-February-1989. Jack Dongarra, Argonne National Laboratory.
Iain Duff, AERE Harwell. Jeremy Du Croz, Numerical Algorithms Group Ltd.
Sven Hammarling, Numerical Algorithms Group Ltd.