zpptrs(3F)

NAME
     ZPPTRS - 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 ZPPTRF

SYNOPSIS
     SUBROUTINE ZPPTRS( UPLO, N, NRHS, AP, B, LDB, INFO )

         CHARACTER      UPLO

         INTEGER        INFO, LDB, N, NRHS

         COMPLEX*16     AP( * ), B( LDB, * )

PURPOSE
     ZPPTRS 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 ZPPTRF.


ARGUMENTS
     UPLO    (input) CHARACTER*1
             = 'U':  Upper triangle of A is stored;
             = 'L':  Lower triangle of A is stored.

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

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

     AP      (input) COMPLEX*16 array, dimension (N*(N+1)/2)
             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 AP as follows:  if
             UPLO = 'U', AP(i + (j-1)*j/2) = U(i,j) for 1<=i<=j; if UPLO =
             'L', AP(i + (j-1)*(2n-j)/2) = L(i,j) for j<=i<=n.

     B       (input/output) COMPLEX*16 array, dimension (LDB,NRHS)
             On entry, the right hand side matrix B.  On exit, the solution
             matrix X.

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

     INFO    (output) INTEGER
             = 0:  successful exit
             < 0:  if INFO = -i, the i-th argument had an illegal value