Exemple #1
0
def _hinv(A00, A01, A11):
    from numpy_sugar import is_all_finite

    rcond = 1e-15
    b = atleast_1d(A01)
    d = atleast_1d(A11)
    a = full_like(d, A00)
    m = maximum(maximum(npy_abs(b), npy_abs(d)), abs(a))

    a /= m
    b = b / m
    c = b
    d = d / m

    bc = b * c
    ad = a * d
    with errstate(invalid="ignore", divide="ignore"):
        ai = a / (a * a - nan_to_num((bc * a) / d))
        bi = b / (b * b - nan_to_num(ad))
        di = d / (d * d - nan_to_num((bc * d) / a))

    ai /= m
    bi /= m
    di /= m

    ok = is_all_finite(ai) and is_all_finite(bi) and is_all_finite(di)
    if not ok:
        ok = logical_and.reduce([isfinite(ai), isfinite(bi), isfinite(di)])
        nok = logical_not(ok)
        U, S, VT = hsvd(a[nok], b[nok], d[nok])

        maxi = maximum(npy_abs(S[0]), npy_abs(S[1]))
        cutoff = rcond * maxi

        large = S[0] > cutoff
        S[0] = divide(1, S[0], where=large, out=S[0])
        S[0][~large] = 0

        large = S[1] > cutoff
        S[1] = divide(1, S[1], where=large, out=S[1])
        S[1][~large] = 0

        SiVT = [[VT[0][0] * S[0], VT[0][1] * S[0]],
                [VT[1][0] * S[1], VT[1][1] * S[1]]]
        Ai = [
            [
                U[0][0] * SiVT[0][0] + U[0][1] * SiVT[1][0],
                U[0][0] * SiVT[0][1] + U[0][1] * SiVT[1][1],
            ],
            [
                U[1][0] * SiVT[0][0] + U[1][1] * SiVT[1][0],
                U[1][0] * SiVT[0][1] + U[1][1] * SiVT[1][1],
            ],
        ]
        ai[nok] = Ai[0][0] / m
        bi[nok] = Ai[0][1] / m
        di[nok] = Ai[1][1] / m

    return ai, bi, di
Exemple #2
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def effsizes_se(effsizes, pvalues):
    r"""Standard errors of the effect sizes.

    Parameters
    ----------
    effsizes : array_like
        Effect sizes.
    pvalues : array_like
        Association significance corresponding to those effect sizes.

    Returns
    -------
    array_like
        Standard errors of the effect sizes.
    """
    from scipy.stats import chi2
    from numpy import abs as npy_abs
    from numpy import sqrt

    return npy_abs(effsizes) / sqrt(chi2(1).isf(pvalues))
Exemple #3
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def _norm(x0, x1):
    m = maximum(npy_abs(x0), npy_abs(x1))
    with errstate(invalid="ignore"):
        a = (x0 / m) * (x0 / m)
        b = (x1 / m) * (x1 / m)
        return nan_to_num(m * sqrt(a + b))
Exemple #4
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def hsolve(A00, A01, A11, y0, y1):
    """
    Solver for the linear equations of two variables and equations only.

    It uses Householder reductions to solve A𝐱 = 𝐲 in a robust manner.

    Parameters
    ----------
    A : array_like
        Coefficient matrix.
    y : array_like
        Ordinate values.

    Returns
    -------
    ndarray
        Solution 𝐱.
    """
    from numpy_sugar import epsilon

    n = _norm(A00, A01)
    u0 = A00 - n
    u1 = A01
    nu = _norm(u0, u1)

    with errstate(invalid="ignore", divide="ignore"):
        v0 = nan_to_num(u0 / nu)
        v1 = nan_to_num(u1 / nu)

    B00 = 1 - 2 * v0 * v0
    B01 = 0 - 2 * v0 * v1
    B11 = 1 - 2 * v1 * v1

    D00 = B00 * A00 + B01 * A01
    D01 = B00 * A01 + B01 * A11
    D11 = B01 * A01 + B11 * A11

    b0 = y0 - 2 * y0 * v0 * v0 - 2 * y1 * v0 * v1
    b1 = y1 - 2 * y0 * v1 * v0 - 2 * y1 * v1 * v1

    n = _norm(D00, D01)
    u0 = D00 - n
    u1 = D01
    nu = _norm(u0, u1)

    with errstate(invalid="ignore", divide="ignore"):
        v0 = nan_to_num(u0 / nu)
        v1 = nan_to_num(u1 / nu)

    E00 = 1 - 2 * v0 * v0
    E01 = 0 - 2 * v0 * v1
    E11 = 1 - 2 * v1 * v1

    F00 = E00 * D00 + E01 * D01
    F01 = E01 * D11
    F11 = E11 * D11

    F11 = (npy_abs(F11) > epsilon.small) * F11

    with errstate(divide="ignore", invalid="ignore"):
        Fi00 = nan_to_num(F00 / F00 / F00)
        Fi11 = nan_to_num(F11 / F11 / F11)
        Fi10 = nan_to_num(-(F01 / F00) * Fi11)

    c0 = Fi00 * b0
    c1 = Fi10 * b0 + Fi11 * b1

    x0 = E00 * c0 + E01 * c1
    x1 = E01 * c0 + E11 * c1

    return array([x0, x1])
Exemple #5
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def hsolve(A, y):
    r"""Solver for the linear equations of two variables and equations only.

    It uses Householder reductions to solve ``Ax = y`` in a robust manner.

    Parameters
    ----------
    A : array_like
        Coefficient matrix.
    y : array_like
        Ordinate values.

    Returns
    -------
    :class:`numpy.ndarray`  Solution ``x``.
    """

    n = _norm(A[0, 0], A[1, 0])
    u0 = A[0, 0] - n
    u1 = A[1, 0]
    nu = _norm(u0, u1)

    with errstate(invalid="ignore", divide="ignore"):
        v0 = nan_to_num(u0 / nu)
        v1 = nan_to_num(u1 / nu)

    B00 = 1 - 2 * v0 * v0
    B01 = 0 - 2 * v0 * v1
    B11 = 1 - 2 * v1 * v1

    D00 = B00 * A[0, 0] + B01 * A[1, 0]
    D01 = B00 * A[0, 1] + B01 * A[1, 1]
    D11 = B01 * A[0, 1] + B11 * A[1, 1]

    b0 = y[0] - 2 * y[0] * v0 * v0 - 2 * y[1] * v0 * v1
    b1 = y[1] - 2 * y[0] * v1 * v0 - 2 * y[1] * v1 * v1

    n = _norm(D00, D01)
    u0 = D00 - n
    u1 = D01
    nu = _norm(u0, u1)

    with errstate(invalid="ignore", divide="ignore"):
        v0 = nan_to_num(u0 / nu)
        v1 = nan_to_num(u1 / nu)

    E00 = 1 - 2 * v0 * v0
    E01 = 0 - 2 * v0 * v1
    E11 = 1 - 2 * v1 * v1

    F00 = E00 * D00 + E01 * D01
    F01 = E01 * D11
    F11 = E11 * D11

    F11 = (npy_abs(F11) > epsilon.small) * F11

    with errstate(divide="ignore", invalid="ignore"):
        Fi00 = nan_to_num(F00 / F00 / F00)
        Fi11 = nan_to_num(F11 / F11 / F11)
        Fi10 = nan_to_num(-(F01 / F00) * Fi11)

    c0 = Fi00 * b0
    c1 = Fi10 * b0 + Fi11 * b1

    x0 = E00 * c0 + E01 * c1
    x1 = E01 * c0 + E11 * c1

    return array([x0, x1])