Zpocon Zpotrf Zpotri Zpotrs Zppcon Zpptrf Zpptri Zpptrs

Zpptrs() Sub Zpptrs ( Uplo As  String, N As  Long, Ap() As  Complex, B() As  Complex, Info As  Long, Optional Nrhs As  Long = 1  ) Solution to factorized system of linear equations AX = B for a Hermitian matrix in packed form Purpose This routine solves a system of linear equations A * X = B with a Hermitian posotive definite matrix A in packed form using the Cholesky factorization A = U^H*U or A = L*L^H computed by Zpptrf. Parameters [in] Uplo = "U": Upper triangular factor U is stored in Ap(). = "L": Lower triangular factor L is stored in Ap(). [in] N Order of the matrix A. (N >= 0) (If N = 0, returns without computation) [in] Ap() Array Ap(LAp - 1) (LAp >= N(N + 1)/2) The triangular factor U or L in packed form from the Cholesky factorization A = U^H*U or A = L*L^H, as computed by Zpptrf. [in,out] B() Array B(LB1 - 1, LB2 - 1) (LB1 >= max(1, N), LB2 >= Nrhs) (2D array) or B(LB - 1) (LB >= max(1, N), Nrhs = 1) (1D array) [in] N x Nrhs matrix of right hand side matrix B. [out] If Info = 0, the N x Nrhs solution matrix X. [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) = -3: The argument Ap() is invalid. = -4: The argument B() is invalid. = -6: The argument Nrhs had an illegal value. (Nrhs < 0) [in] Nrhs (Optional) Number of right hand sides, i.e., number of columns of the matrix B. (Nrhs >= 0) (If Nrhs = 0, returns without computation) (default = 1) Reference LAPACK Example Program See example of Zpptrf.