ctrsm-f(3)

ctrsm.f –

Synopsis

Functions/Subroutines

subroutine ctrsm (SIDE, UPLO, TRANSA, DIAG, M, N, ALPHA, A, LDA, B, LDB)
CTRSM

Function/Subroutine Documentation

subroutine ctrsm (characterSIDE, characterUPLO, characterTRANSA, characterDIAG, integerM, integerN, complexALPHA, complex, dimension(lda,)A, integerLDA, complex, dimension(ldb,)B, integerLDB)

CTRSM Purpose:

 CTRSM 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**T or op( A ) = A**H.
 The matrix X is overwritten on B.

Parameters:

SIDE

 SIDE is CHARACTER*1
 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.

UPLO

 UPLO is 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.

TRANSA

 TRANSA is 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**T.
 TRANSA = 'C' or 'c' op( A ) = A**H.

DIAG

 DIAG is 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.

 M is INTEGER
 On entry, M specifies the number of rows of B. M must be at
 least zero.

 N is INTEGER
 On entry, N specifies the number of columns of B. N must be
 at least zero.

ALPHA

 ALPHA is COMPLEX
 On entry, ALPHA specifies the scalar alpha. When alpha is
 zero then A is not referenced and B need not be set before
 entry.

 A is COMPLEX array of DIMENSION ( LDA, k ),
 where k is m when SIDE = 'L' or 'l' 
 and k 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.

LDA

 LDA is 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 ).

 B is COMPLEX 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

 LDB is 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 ).

Author:

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date:

November 2011

Further Details:

 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.

Definition at line 181 of file ctrsm.f.

Author