dsysv_aa_2stage function

Implementation

void dsysv_aa_2stage(
  final String UPLO,
  final int N,
  final int NRHS,
  final Matrix<double> A_,
  final int LDA,
  final Array<double> TB_,
  final int LTB,
  final Array<int> IPIV_,
  final Array<int> IPIV2_,
  final Matrix<double> B_,
  final int LDB,
  final Array<double> WORK_,
  final int LWORK,
  final Box<int> INFO,
) {
  final A = A_.having(ld: LDA);
  final TB = TB_.having();
  final IPIV = IPIV_.having();
  final IPIV2 = IPIV2_.having();
  final B = B_.having(ld: LDB);
  final WORK = WORK_.having();
  bool UPPER, TQUERY, WQUERY;
  int LWKMIN, LWKOPT = 0;

  // Test the input parameters.

  INFO.value = 0;
  UPPER = lsame(UPLO, 'U');
  WQUERY = (LWORK == -1);
  TQUERY = (LTB == -1);
  LWKMIN = max(1, N);
  if (!UPPER && !lsame(UPLO, 'L')) {
    INFO.value = -1;
  } else if (N < 0) {
    INFO.value = -2;
  } else if (NRHS < 0) {
    INFO.value = -3;
  } else if (LDA < max(1, N)) {
    INFO.value = -5;
  } else if (LTB < max(1, 4 * N) && !TQUERY) {
    INFO.value = -7;
  } else if (LDB < max(1, N)) {
    INFO.value = -11;
  } else if (LWORK < LWKMIN && !WQUERY) {
    INFO.value = -13;
  }

  if (INFO.value == 0) {
    dsytrf_aa_2stage(UPLO, N, A, LDA, TB, -1, IPIV, IPIV2, WORK, -1, INFO);
    LWKOPT = max(LWKMIN, WORK[1].toInt());
    WORK[1] = LWKOPT.toDouble();
  }

  if (INFO.value != 0) {
    xerbla('DSYSV_AA_2STAGE', -INFO.value);
    return;
  } else if (WQUERY || TQUERY) {
    return;
  }

  // Compute the factorization A = U**T*T*U or A = L*T*L**T.

  dsytrf_aa_2stage(UPLO, N, A, LDA, TB, LTB, IPIV, IPIV2, WORK, LWORK, INFO);
  if (INFO.value == 0) {
    // Solve the system A*X = B, overwriting B with X.

    dsytrs_aa_2stage(UPLO, N, NRHS, A, LDA, TB, LTB, IPIV, IPIV2, B, LDB, INFO);
  }

  WORK[1] = LWKOPT.toDouble();
}