ZPPTRS(3)      LAPACK routine of NEC Numeric Library Collection      ZPPTRS(3)



NAME
       ZPPTRS

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



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

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

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

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

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

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



LAPACK routine                  31 October 2017                      ZPPTRS(3)