Contents

• NAME
• SYNOPSIS
  • F95 INTERFACE
  • C INTERFACE
• PURPOSE
• ARGUMENTS

NAME

     chptrs - solve a system of linear equations A*X = B  with  a
     complex Hermitian matrix A stored in packed format using the
     factorization A = U*D*U**H  or  A  =  L*D*L**H  computed  by
     CHPTRF

SYNOPSIS

     SUBROUTINE CHPTRS(UPLO, N, NRHS, A, IPIVOT, B, LDB, INFO)

     CHARACTER * 1 UPLO
     COMPLEX A(*), B(LDB,*)
     INTEGER N, NRHS, LDB, INFO
     INTEGER IPIVOT(*)

     SUBROUTINE CHPTRS_64(UPLO, N, NRHS, A, IPIVOT, B, LDB, INFO)

     CHARACTER * 1 UPLO
     COMPLEX A(*), B(LDB,*)
     INTEGER*8 N, NRHS, LDB, INFO
     INTEGER*8 IPIVOT(*)

  F95 INTERFACE
     SUBROUTINE HPTRS(UPLO, N, [NRHS], A, IPIVOT, B, [LDB], [INFO])

     CHARACTER(LEN=1) :: UPLO
     COMPLEX, DIMENSION(:) :: A
     COMPLEX, DIMENSION(:,:) :: B
     INTEGER :: N, NRHS, LDB, INFO
     INTEGER, DIMENSION(:) :: IPIVOT

     SUBROUTINE HPTRS_64(UPLO, N, [NRHS], A, IPIVOT, B, [LDB], [INFO])

     CHARACTER(LEN=1) :: UPLO
     COMPLEX, DIMENSION(:) :: A
     COMPLEX, DIMENSION(:,:) :: B
     INTEGER(8) :: N, NRHS, LDB, INFO
     INTEGER(8), DIMENSION(:) :: IPIVOT

  C INTERFACE
     #include <sunperf.h>

     void chptrs(char uplo, int n,  int  nrhs,  complex  *a,  int
               *ipivot, complex *b, int ldb, int *info);

     void chptrs_64(char uplo, long n,  long  nrhs,  complex  *a,
               long *ipivot, complex *b, long ldb, long *info);

PURPOSE

     chptrs solves a system of linear equations A*X =  B  with  a
     complex Hermitian matrix A stored in packed format using the
     factorization A = U*D*U**H  or  A  =  L*D*L**H  computed  by
     CHPTRF.

ARGUMENTS

     UPLO (input)
               Specifies whether the details of the factorization
               are stored as an upper or lower triangular matrix.
               = 'U':  Upper triangular, form is A = U*D*U**H;
               = 'L':  Lower triangular, form is A = L*D*L**H.

     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 block diagonal matrix D  and  the  multipliers
               used  to  obtain  the factor U or L as computed by
               CHPTRF, stored as a packed triangular matrix.

     IPIVOT (input)
               Details of the interchanges and the  block  struc-
               ture of D as determined by CHPTRF.

     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)
               = 0:  successful exit
               < 0: if INFO = -i, the i-th argument had an  ille-
               gal value