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

NAME

cpptrs - solve a system of linear equations A*X = B with a Hermitian positive definite matrix A in packed storage using the Cholesky factorization A = U**H*U or A = L*L**H computed by CPPTRF

SYNOPSIS

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

  SUBROUTINE CPPTRS_64( UPLO, N, NRHS, A, B, LDB, INFO)
  CHARACTER * 1 UPLO
  COMPLEX A(*), B(LDB,*)
  INTEGER*8 N, NRHS, LDB, INFO

F95 INTERFACE

  SUBROUTINE PPTRS( UPLO, N, [NRHS], A, B, [LDB], [INFO])
  CHARACTER(LEN=1) :: UPLO
  COMPLEX, DIMENSION(:) :: A
  COMPLEX, DIMENSION(:,:) :: B
  INTEGER :: N, NRHS, LDB, INFO

  SUBROUTINE PPTRS_64( UPLO, N, [NRHS], A, B, [LDB], [INFO])
  CHARACTER(LEN=1) :: UPLO
  COMPLEX, DIMENSION(:) :: A
  COMPLEX, DIMENSION(:,:) :: B
  INTEGER(8) :: N, NRHS, LDB, INFO

C INTERFACE

#include <sunperf.h>

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

void cpptrs_64(char uplo, long n, long nrhs, complex *a, complex *b, long ldb, long *info);

PURPOSE

cpptrs solves a system of linear equations A*X = B with a Hermitian positive definite matrix A in packed storage using the Cholesky factorization A = U**H*U or A = L*L**H computed by CPPTRF.

ARGUMENTS

• UPLO (input)
  

   = 'U':  Upper triangle of A is stored;

   = 'L':  Lower triangle of A is stored.

• 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 factor U or L from the Cholesky factorization A = U**H*U or A = L*L**H, packed columnwise in a linear array. The j-th column of U or L is stored in the array A as follows: if UPLO = 'U', A(i + (j-1)*j/2) = U(i,j) for 1 < =i < =j; if UPLO = 'L', A(i + (j-1)*(2n-j)/2) = L(i,j) for j < =i < =n.

• 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 illegal value