strtrs

NAME

strtrs - solve a triangular system of the form A * X = B or A**T * X = B,

SYNOPSIS

  SUBROUTINE STRTRS( UPLO, TRANSA, DIAG, N, NRHS, A, LDA, B, LDB, 
 *      INFO)
  CHARACTER * 1 UPLO, TRANSA, DIAG
  INTEGER N, NRHS, LDA, LDB, INFO
  REAL A(LDA,*), B(LDB,*)
 
  SUBROUTINE STRTRS_64( UPLO, TRANSA, DIAG, N, NRHS, A, LDA, B, LDB, 
 *      INFO)
  CHARACTER * 1 UPLO, TRANSA, DIAG
  INTEGER*8 N, NRHS, LDA, LDB, INFO
  REAL A(LDA,*), B(LDB,*)

F95 INTERFACE

  SUBROUTINE TRTRS( UPLO, [TRANSA], DIAG, N, NRHS, A, [LDA], B, [LDB], 
 *       [INFO])
  CHARACTER(LEN=1) :: UPLO, TRANSA, DIAG
  INTEGER :: N, NRHS, LDA, LDB, INFO
  REAL, DIMENSION(:,:) :: A, B
 
  SUBROUTINE TRTRS_64( UPLO, [TRANSA], DIAG, N, NRHS, A, [LDA], B, 
 *       [LDB], [INFO])
  CHARACTER(LEN=1) :: UPLO, TRANSA, DIAG
  INTEGER(8) :: N, NRHS, LDA, LDB, INFO
  REAL, DIMENSION(:,:) :: A, B

C INTERFACE

#include <sunperf.h>

void strtrs(char uplo, char transa, char diag, int n, int nrhs, float *a, int lda, float *b, int ldb, int *info);

void strtrs_64(char uplo, char transa, char diag, long n, long nrhs, float *a, long lda, float *b, long ldb, long *info);

PURPOSE

strtrs solves a triangular system of the form

where A is a triangular matrix of order N, and B is an N-by-NRHS matrix. A check is made to verify that A is nonsingular.

ARGUMENTS

* UPLO (input)
* TRANSA (input): Specifies the form of the system of equations:
* DIAG (input)
* N (input): The order of the matrix A. N >= 0.
* NRHS (input): The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.
* A (input): The triangular matrix A. If UPLO = 'U', the leading N-by-N upper triangular part of the array A contains the upper triangular matrix, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading N-by-N lower triangular part of the array A contains the lower triangular matrix, and the strictly upper triangular part of A is not referenced. If DIAG = 'U', the diagonal elements of A are also not referenced and are assumed to be 1.
* LDA (input): The leading dimension of the array A. LDA >= max(1,N).
* B (input/output): On entry, the right hand side matrix B. On exit, if INFO = 0, the solution matrix X.
* LDB (input): The leading dimension of the array B. LDB >= max(1,N).
* INFO (output)