SRC/zppsv.f(3)             Library Functions Manual             SRC/zppsv.f(3)

NAME
       SRC/zppsv.f

SYNOPSIS
   Functions/Subroutines
       subroutine zppsv (uplo, n, nrhs, ap, b, ldb, info)
            ZPPSV computes the solution to system of linear equations A * X =
           B for OTHER matrices

Function/Subroutine Documentation
   subroutine zppsv (character uplo, integer n, integer nrhs, complex*16,
       dimension( * ) ap, complex*16, dimension( ldb, * ) b, integer ldb,
       integer info)
        ZPPSV computes the solution to system of linear equations A * X = B
       for OTHER matrices

       Purpose:


            ZPPSV 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.

       Parameters
           UPLO

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

           N

                     N is INTEGER
                     The number of linear equations, i.e., the order of the
                     matrix A.  N >= 0.

           NRHS

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

           AP

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

                     B is COMPLEX*16 array, dimension (LDB,NRHS)
                     On entry, the N-by-NRHS right hand side matrix B.
                     On exit, if INFO = 0, the N-by-NRHS solution matrix X.

           LDB

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

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value
                     > 0:  if INFO = i, the leading principal minor of order i
                           of A is not positive, so the factorization could not
                           be completed, and the solution has not been computed.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:


             The packed storage scheme is illustrated by the following example
             when N = 4, UPLO = 'U':

             Two-dimensional storage of the Hermitian matrix A:

                a11 a12 a13 a14
                    a22 a23 a24
                        a33 a34     (aij = conjg(aji))
                            a44

             Packed storage of the upper triangle of A:

             AP = [ a11, a12, a22, a13, a23, a33, a14, a24, a34, a44 ]

       Definition at line 143 of file zppsv.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0                  SRC/zppsv.f(3)