strsm.f man page

strsm.f —

Synopsis

Functions/Subroutines

subroutine strsm (SIDE, UPLO, TRANSA, DIAG, M, N, ALPHA, A, LDA, B, LDB)
STRSM

Function/Subroutine Documentation

subroutine strsm (characterSIDE, characterUPLO, characterTRANSA, characterDIAG, integerM, integerN, realALPHA, real, dimension(lda,*)A, integerLDA, real, dimension(ldb,*)B, integerLDB)

STRSM Purpose:

STRSM  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.

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**T.

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

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

N

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

ALPHA

ALPHA is REAL
 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

A is REAL 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

B is REAL 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 182 of file strsm.f.

Author

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Referenced By

strsm(3) is an alias of strsm.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK