zpocon zpotrf zpotri zpotrs zppcon zpptrf zpptri zpptrs

zpptrf() void zpptrf ( char  uplo, int  n, doublecomplex  ap[], int *  info  ) Cholesky factorization of a Hermitian positive definite matrix in packed form Purpose This routine computes the Cholesky factorization of a Hermitian positive definite matrix A stored in packed form. 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 a lower triangular matrix. Parameters [in] uplo = 'U': Upper triangle of A is stored. = 'L': Lower triangle of A is stored. [in] n Order of the matrix A. (n >= 0) (If n = 0, returns without computation) [in,out] ap[] Array ap[lap] (lap >= n(n + 1)/2) [in] n x n Hermitian positove definite matrix A in packed form. The upper or lower part is to be stored in accordance with uplo. [out] If info = 0, the factor U or L from the Cholesky factorization A = U^H*U or A = L*L^H. [out] info = 0: Successful exit = -1: The argument uplo had an illegal value (uplo != 'U' nor 'L') = -2: The argument n had an illegal value (n < 0) = i > 0: The leading minor of order i is not positive definite, and the factorization could not be completed. Reference LAPACK