ctbtrs (3p)

Name

ctbtrs - solve a triangular system of the form A*X = B, A**T*X = B, or A**H*X = B, where A is a triangular band matrix of order N, and B is an N-by-NRHS matrix

Synopsis

SUBROUTINE CTBTRS(UPLO, TRANSA, DIAG, N, KD, NRHS, A, LDA, B, LDB,
INFO)

CHARACTER*1 UPLO, TRANSA, DIAG
COMPLEX A(LDA,*), B(LDB,*)
INTEGER N, KD, NRHS, LDA, LDB, INFO

SUBROUTINE CTBTRS_64(UPLO, TRANSA, DIAG, N, KD, NRHS, A, LDA, B,
LDB, INFO)

CHARACTER*1 UPLO, TRANSA, DIAG
COMPLEX A(LDA,*), B(LDB,*)
INTEGER*8 N, KD, NRHS, LDA, LDB, INFO




F95 INTERFACE
SUBROUTINE TBTRS(UPLO, TRANSA, DIAG, N, KD, NRHS, A, LDA, B,
LDB, INFO)

CHARACTER(LEN=1) :: UPLO, TRANSA, DIAG
COMPLEX, DIMENSION(:,:) :: A, B
INTEGER :: N, KD, NRHS, LDA, LDB, INFO

SUBROUTINE TBTRS_64(UPLO, TRANSA, DIAG, N, KD, NRHS, A, LDA,
B, LDB, INFO)

CHARACTER(LEN=1) :: UPLO, TRANSA, DIAG
COMPLEX, DIMENSION(:,:) :: A, B
INTEGER(8) :: N, KD, NRHS, LDA, LDB, INFO




C INTERFACE
#include <sunperf.h>

void ctbtrs(char uplo, char transa, char diag, int n, int kd, int nrhs,
complex *a, int lda, complex *b, int ldb, int *info);

void ctbtrs_64(char uplo, char transa, char diag, long n, long kd, long
nrhs,  complex  *a,  long  lda,  complex  *b,  long ldb, long
*info);

Description

Oracle Solaris Studio Performance Library                           ctbtrs(3P)



NAME
       ctbtrs  - solve a triangular system of the form A*X = B, A**T*X = B, or
       A**H*X = B, where A is a triangular band matrix of order N, and B is an
       N-by-NRHS matrix


SYNOPSIS
       SUBROUTINE CTBTRS(UPLO, TRANSA, DIAG, N, KD, NRHS, A, LDA, B, LDB,
             INFO)

       CHARACTER*1 UPLO, TRANSA, DIAG
       COMPLEX A(LDA,*), B(LDB,*)
       INTEGER N, KD, NRHS, LDA, LDB, INFO

       SUBROUTINE CTBTRS_64(UPLO, TRANSA, DIAG, N, KD, NRHS, A, LDA, B,
             LDB, INFO)

       CHARACTER*1 UPLO, TRANSA, DIAG
       COMPLEX A(LDA,*), B(LDB,*)
       INTEGER*8 N, KD, NRHS, LDA, LDB, INFO




   F95 INTERFACE
       SUBROUTINE TBTRS(UPLO, TRANSA, DIAG, N, KD, NRHS, A, LDA, B,
              LDB, INFO)

       CHARACTER(LEN=1) :: UPLO, TRANSA, DIAG
       COMPLEX, DIMENSION(:,:) :: A, B
       INTEGER :: N, KD, NRHS, LDA, LDB, INFO

       SUBROUTINE TBTRS_64(UPLO, TRANSA, DIAG, N, KD, NRHS, A, LDA,
              B, LDB, INFO)

       CHARACTER(LEN=1) :: UPLO, TRANSA, DIAG
       COMPLEX, DIMENSION(:,:) :: A, B
       INTEGER(8) :: N, KD, NRHS, LDA, LDB, INFO




   C INTERFACE
       #include <sunperf.h>

       void ctbtrs(char uplo, char transa, char diag, int n, int kd, int nrhs,
                 complex *a, int lda, complex *b, int ldb, int *info);

       void ctbtrs_64(char uplo, char transa, char diag, long n, long kd, long
                 nrhs,  complex  *a,  long  lda,  complex  *b,  long ldb, long
                 *info);



PURPOSE
       ctbtrs solves a triangular system of the form

       A * X = B, A**T * X = B, or A**H * X = B

       where A is a triangular band 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)
                 = 'U':  A is upper triangular;
                 = 'L':  A is lower triangular.


       TRANSA (input)
                 Specifies the form of the system of equations:
                 = 'N':  A * X = B     (No transpose)
                 = 'T':  A**T * X = B  (Transpose)
                 = 'C':  A**H * X = B  (Conjugate transpose)


       DIAG (input)
                 = 'N':  A is non-unit triangular;
                 = 'U':  A is unit triangular.


       N (input) The order of the matrix A.  N >= 0.


       KD (input)
                 The  number of superdiagonals or subdiagonals of the triangu-
                 lar band matrix A.  KD >= 0.


       NRHS (input)
                 The number of right hand sides, i.e., the number  of  columns
                 of the matrix B.  NRHS >= 0.


       A (input) The  upper  or  lower triangular band matrix A, stored in the
                 first kd+1 rows of A.  The j-th column of A is stored in  the
                 j-th  column  of  the  array  A  as  follows:  if UPLO = 'U',
                 A(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j; if UPLO =  'L',
                 A(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+kd).  If DIAG = 'U',
                 the diagonal elements of A are not referenced and are assumed
                 to be 1.


       LDA (input)
                 The leading dimension of the array A.  LDA >= KD+1.


       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)
                 = 0:  successful exit
                 < 0:  if INFO = -i, the i-th argument had an illegal value
                 > 0:  if INFO = i, the i-th diagonal element of  A  is  zero,
                 indicating  that  the  matrix is singular and the solutions X
                 have not been computed.




                                  7 Nov 2015                        ctbtrs(3P)