cppsv

NAME

cppsv - compute the solution to a complex system of linear equations A * X = B,

SYNOPSIS 

  SUBROUTINE CPPSV( UPLO, N, NRHS, A, B, LDB, INFO)
  CHARACTER * 1 UPLO
  COMPLEX A(*), B(LDB,*)
  INTEGER N, NRHS, LDB, INFO
 
  SUBROUTINE CPPSV_64( UPLO, N, NRHS, A, B, LDB, INFO)
  CHARACTER * 1 UPLO
  COMPLEX A(*), B(LDB,*)
  INTEGER*8 N, NRHS, LDB, INFO

F95 INTERFACE 

  SUBROUTINE PPSV( UPLO, N, [NRHS], A, B, [LDB], [INFO])
  CHARACTER(LEN=1) :: UPLO
  COMPLEX, DIMENSION(:) :: A
  COMPLEX, DIMENSION(:,:) :: B
  INTEGER :: N, NRHS, LDB, INFO
 
  SUBROUTINE PPSV_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 cppsv(char uplo, int n, int nrhs, complex *a, complex *b, int ldb, int *info);

void cppsv_64(char uplo, long n, long nrhs, complex *a, complex *b, long ldb, long *info);

PURPOSE

cppsv computes the solution to a complex system of linear equations A * X = B, where A is an N-by-N Hermitian positive definite matrix stored in packed format and X and B are N-by-NRHS matrices.

The Cholesky decomposition is used to factor A as 

   A = U**H* U,  if UPLO = 'U', or
   A = L * L**H,  if UPLO = 'L',

where U is an upper triangular matrix and L is a lower triangular matrix. The factored form of A is then used to solve the system of equations A * X = B.

ARGUMENTS

* UPLO (input)
* 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 upper or lower triangle of the Hermitian matrix A, packed columnwise in a linear array. The j-th column of A is stored in the array A as follows: if UPLO = 'U', A(i + (j-1)*j/2) = A(i,j) for 1<=i<=j; if UPLO = 'L', A(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n. See below for further details.

On exit, if INFO = 0, the factor U or L from the Cholesky factorization A = U**H*U or A = L*L**H, in the same storage format as A.

* 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).

* INFO (output)