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Updated: June 2017
 
 

csysv_rook (3p)

Name

csysv_rook - compute the solution to system of linear equations A*X = B for symmetric matrices. CSYTRF_ROOK is called to compute the factoriza- tion of A

Synopsis

SUBROUTINE CSYSV_ROOK(UPLO, N, NRHS, A, LDA, IPIV, B, LDB, WORK, LWORK,
INFO)

CHARACTER*1 UPLO
COMPLEX A(LDA,*), B(LDB,*), WORK(*)
INTEGER N, NRHS, LDA, LDB, LWORK, INFO
INTEGER IPIV(*)

SUBROUTINE CSYSV_ROOK_64(UPLO, N, NRHS, A, LDA, IPIV, B, LDB, WORK, LWORK,
INFO)

CHARACTER*1 UPLO
COMPLEX A(LDA,*), B(LDB,*), WORK(*)
INTEGER*8 N, NRHS, LDA, LDB, LWORK, INFO
INTEGER*8 IPIV(*)




F95 INTERFACE
SUBROUTINE SYSV_ROOK(UPLO, N, NRHS, A, LDA, IPIV, B, LDB, WORK,
LWORK, INFO)

CHARACTER(LEN=1) :: UPLO
COMPLEX, DIMENSION(:) :: WORK
COMPLEX, DIMENSION(:,:) :: A, B
INTEGER :: N, NRHS, LDA, LDB, LWORK, INFO
INTEGER, DIMENSION(:) :: IPIV

UBROUTINE SYSV_ROOK_64(UPLO, N, NRHS, A, LDA, IPIV, B, LDB, WORK,
LWORK, INFO)

CHARACTER(LEN=1) :: UPLO
COMPLEX, DIMENSION(:) :: WORK
COMPLEX, DIMENSION(:,:) :: A, B
INTEGER(8) :: N, NRHS, LDA, LDB, LWORK, INFO
INTEGER(8), DIMENSION(:) :: IPIV




C INTERFACE
#include <sunperf.h>

void  csysv_rook(char  uplo,  int n, int nrhs, complex *a, int lda, int
*ipiv, complex *b, int ldb, int *info);

void csysv_rook_64(char uplo, long n, long nrhs, complex *a, long  lda,
long *ipiv, complex *b, long ldb, long *info);

Description

Oracle Solaris Studio Performance Library                       csysv_rook(3P)



NAME
       csysv_rook - compute the solution to system of linear equations A*X = B
       for symmetric matrices. CSYTRF_ROOK is called to compute the factoriza-
       tion of A


SYNOPSIS
       SUBROUTINE CSYSV_ROOK(UPLO, N, NRHS, A, LDA, IPIV, B, LDB, WORK, LWORK,
             INFO)

       CHARACTER*1 UPLO
       COMPLEX A(LDA,*), B(LDB,*), WORK(*)
       INTEGER N, NRHS, LDA, LDB, LWORK, INFO
       INTEGER IPIV(*)

       SUBROUTINE CSYSV_ROOK_64(UPLO, N, NRHS, A, LDA, IPIV, B, LDB, WORK, LWORK,
             INFO)

       CHARACTER*1 UPLO
       COMPLEX A(LDA,*), B(LDB,*), WORK(*)
       INTEGER*8 N, NRHS, LDA, LDB, LWORK, INFO
       INTEGER*8 IPIV(*)




   F95 INTERFACE
       SUBROUTINE SYSV_ROOK(UPLO, N, NRHS, A, LDA, IPIV, B, LDB, WORK,
              LWORK, INFO)

       CHARACTER(LEN=1) :: UPLO
       COMPLEX, DIMENSION(:) :: WORK
       COMPLEX, DIMENSION(:,:) :: A, B
       INTEGER :: N, NRHS, LDA, LDB, LWORK, INFO
       INTEGER, DIMENSION(:) :: IPIV

       UBROUTINE SYSV_ROOK_64(UPLO, N, NRHS, A, LDA, IPIV, B, LDB, WORK,
              LWORK, INFO)

       CHARACTER(LEN=1) :: UPLO
       COMPLEX, DIMENSION(:) :: WORK
       COMPLEX, DIMENSION(:,:) :: A, B
       INTEGER(8) :: N, NRHS, LDA, LDB, LWORK, INFO
       INTEGER(8), DIMENSION(:) :: IPIV




   C INTERFACE
       #include <sunperf.h>

       void  csysv_rook(char  uplo,  int n, int nrhs, complex *a, int lda, int
                 *ipiv, complex *b, int ldb, int *info);

       void csysv_rook_64(char uplo, long n, long nrhs, complex *a, long  lda,
                 long *ipiv, complex *b, long ldb, long *info);



PURPOSE
       csysv_rook  computes  the  solution to a complex system of linear equa-
       tions
          A * X = B, where A is an N-by-N symmetric matrix and X and B are  N-
       by-NRHS matrices.

       The diagonal pivoting method is used to factor A as
          A = U * D * U**T,  if UPLO = 'U', or
          A = L * D * L**T,  if UPLO = 'L',
       where  U (or L) is a product of permutation and unit upper (lower) tri-
       angular matrices, and D is symmetric and block diagonal with 1-by-1 and
       2-by-2  diagonal  blocks.  The factored form of A is then used to solve
       the system of equations A * X = B.
       CSYTRF_ROOK is called to compute the factorization of a complex symmet-
       ric matrix A using the bounded Bunch-Kaufman ("rook") diagonal pivoting
       method.


ARGUMENTS
       UPLO (input)
                 = 'U':  Upper triangle of A is stored;
                 = 'L':  Lower triangle of A is stored.


       N (input) The number of linear equations, i.e., 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/output)
                 On entry, the symmetric matrix A.  If UPLO = 'U', the leading
                 N-by-N upper triangular part of A contains the upper triangu-
                 lar part of the matrix A, and the strictly  lower  triangular
                 part  of  A is not referenced.  If UPLO = 'L', the leading N-
                 by-N lower triangular part of A contains the lower triangular
                 part  of the matrix A, and the strictly upper triangular part
                 of A is not referenced.

                 On exit, if INFO = 0, the block diagonal  matrix  D  and  the
                 multipliers used to obtain the factor U or L from the factor-
                 ization  A  =  U*D*U**T  or  A  =  L*D*L**T  as  computed  by
                 CSYTRF_ROOK.


       LDA (input)
                 The leading dimension of the array A. LDA >= max(1,N).


       IPIV (output)
                 Details  of the interchanges and the block structure of D, as
                 determined by CSYTRF_ROOK. If IPIV(k) > 0, then rows and col-
                 umns  k and IPIV(k) were interchanged, and D(k,k) is a 1-by-1
                 diagonal block. If UPLO = 'U' and IPIV(k) =  IPIV(k-1)  <  0,
                 then  rows and columns k-1 and -IPIV(k) were interchanged and
                 D(k-1:k,k-1:k) is a 2-by-2 diagonal block. If UPLO = 'L'  and
                 IPIV(k)  =  IPIV(k+1)  <  0,  then  rows  and columns k+1 and
                 -IPIV(k) were interchanged and  D(k:k+1,k:k+1)  is  a  2-by-2
                 diagonal block.


       B (input/output)
                 On  entry,  the N-by-NRHS right hand side matrix B.  On exit,
                 if INFO = 0, the N-by-NRHS solution matrix X.


       LDB (input)
                 The leading dimension of the array B. LDB >= max(1,N).


       WORK (workspace)
                 On exit, if INFO = 0, WORK(1) returns the optimal LWORK.


       LWORK (input)
                 The length of WORK. LWORK >=  1,  and  for  best  performance
                 LWORK  >=  N*NB,  where  NB  is  the  optimal  blocksize  for
                 CSYTRF_ROOK.

                 If LWORK = -1, then a workspace query is assumed; the routine
                 only  calculates  the optimal size of the WORK array, returns
                 this value as the first entry of the WORK array, and no error
                 message related to LWORK is issued by XERBLA.


       INFO (output)
                 = 0: successful exit;
                 < 0: if INFO = -i, the i-th argument had an illegal value;
                 >  0: if INFO = i, D(i,i) is exactly zero.  The factorization
                 has been completed,  but  the  block  diagonal  matrix  D  is
                 exactly singular, so the solution could not be computed.




                                  7 Nov 2015                    csysv_rook(3P)