cgbtrs

NAME

cgbtrs - solve a system of linear equations A * X = B, A**T * X = B, or A**H * X = B with a general band matrix A using the LU factorization computed by CGBTRF

SYNOPSIS

  SUBROUTINE CGBTRS( TRANSA, N, NSUB, NSUPER, NRHS, A, LDA, IPIVOT, B, 
 *      LDB, INFO)
  CHARACTER * 1 TRANSA
  COMPLEX A(LDA,*), B(LDB,*)
  INTEGER N, NSUB, NSUPER, NRHS, LDA, LDB, INFO
  INTEGER IPIVOT(*)
 
  SUBROUTINE CGBTRS_64( TRANSA, N, NSUB, NSUPER, NRHS, A, LDA, IPIVOT, 
 *      B, LDB, INFO)
  CHARACTER * 1 TRANSA
  COMPLEX A(LDA,*), B(LDB,*)
  INTEGER*8 N, NSUB, NSUPER, NRHS, LDA, LDB, INFO
  INTEGER*8 IPIVOT(*)

F95 INTERFACE

  SUBROUTINE GBTRS( [TRANSA], [N], NSUB, NSUPER, [NRHS], A, [LDA], 
 *       IPIVOT, B, [LDB], [INFO])
  CHARACTER(LEN=1) :: TRANSA
  COMPLEX, DIMENSION(:,:) :: A, B
  INTEGER :: N, NSUB, NSUPER, NRHS, LDA, LDB, INFO
  INTEGER, DIMENSION(:) :: IPIVOT
 
  SUBROUTINE GBTRS_64( [TRANSA], [N], NSUB, NSUPER, [NRHS], A, [LDA], 
 *       IPIVOT, B, [LDB], [INFO])
  CHARACTER(LEN=1) :: TRANSA
  COMPLEX, DIMENSION(:,:) :: A, B
  INTEGER(8) :: N, NSUB, NSUPER, NRHS, LDA, LDB, INFO
  INTEGER(8), DIMENSION(:) :: IPIVOT

C INTERFACE

#include <sunperf.h>

void cgbtrs(char transa, int n, int nsub, int nsuper, int nrhs, complex *a, int lda, int *ipivot, complex *b, int ldb, int *info);

void cgbtrs_64(char transa, long n, long nsub, long nsuper, long nrhs, complex *a, long lda, long *ipivot, complex *b, long ldb, long *info);

PURPOSE

cgbtrs solves a system of linear equations A * X = B, A**T * X = B, or A**H * X = B with a general band matrix A using the LU factorization computed by CGBTRF.

ARGUMENTS

* TRANSA (input): Specifies the form of the system of equations.
* N (input): The order of the matrix A. N >= 0.
* NSUB (input): The number of subdiagonals within the band of A. NSUB >= 0.
* NSUPER (input): The number of superdiagonals within the band of A. NSUPER >= 0.
* NRHS (input): The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0.
* A (input): Details of the LU factorization of the band matrix A, as computed by CGBTRF. U is stored as an upper triangular band matrix with NSUB+NSUPER superdiagonals in rows 1 to NSUB+NSUPER+1, and the multipliers used during the factorization are stored in rows NSUB+NSUPER+2 to 2*NSUB+NSUPER+1.
* LDA (input): The leading dimension of the array A. LDA >= 2*NSUB+NSUPER+1.
* IPIVOT (input): The pivot indices; for 1 <= i <= N, row i of the matrix was interchanged with row IPIVOT(i).
* B (input/output): On entry, the right hand side matrix B. On exit, the solution matrix X.
* LDB (input): The leading dimension of the array B. LDB >= max(1,N).
* INFO (output)