cpotrf(3F)

NAME
     CPOTRF - compute the Cholesky factorization of a complex Hermitian
     positive definite matrix A

SYNOPSIS
     SUBROUTINE CPOTRF( UPLO, N, A, LDA, INFO )

         CHARACTER      UPLO

         INTEGER        INFO, LDA, N

         COMPLEX        A( LDA, * )

PURPOSE
     CPOTRF computes the Cholesky factorization of a complex Hermitian
     positive definite matrix A.

     The factorization has the form
        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 lower triangular.

     This is the block version of the algorithm, calling Level 3 BLAS.


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.

     A       (input/output) COMPLEX array, dimension (LDA,N)
             On entry, the Hermitian matrix A.  If UPLO = 'U', the leading N-
             by-N upper triangular part of A contains the upper triangular
             part of the matrix A, and the strictly lower triangular part of A
             is not referenced.  If UPLO = 'L', the leading N-by-N lower
             triangular part of A contains the lower triangular part of the
             matrix A, and the strictly upper triangular part of A is not
             referenced.

             On exit, if INFO = 0, the factor U or L from the Cholesky
             factorization A = U**H*U or A = L*L**H.

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

     INFO    (output) INTEGER
             = 0:  successful exit
             < 0:  if INFO = -i, the i-th argument had an illegal value
             > 0:  if INFO = i, the leading minor of order i is not positive
             definite, and the factorization could not be completed.