0ab9eb0daf419e000680f162e25220a60c145cf5,scipy/optimize/linesearch.py,,_cubicmin,#Any#Any#Any#Any#Any#Any#Any#,397

Before Change

    C = fpa
    db = b - a
    dc = c - a
    if (db == 0) or (dc == 0) or (b == c):
        return None
    denom = (db * dc) ** 2 * (db - dc)
    d1 = np.empty((2, 2))
    d1[0, 0] = dc ** 2
    d1[0, 1] = -db ** 2

After Change

    
    // f(x) = A *(x-a)^3 + B*(x-a)^2 + C*(x-a) + D

    with np.errstate(divide="raise", over="raise", invalid="raise"):
        try:
            C = fpa
            db = b - a
            dc = c - a
            denom = (db * dc) ** 2 * (db - dc)
            d1 = np.empty((2, 2))
            d1[0, 0] = dc ** 2
            d1[0, 1] = -db ** 2
            d1[1, 0] = -dc ** 3
            d1[1, 1] = db ** 3
            [A, B] = np.dot(d1, np.asarray([fb - fa - C * db,
                                            fc - fa - C * dc]).flatten())
            A /= denom
            B /= denom
            radical = B * B - 3 * A * C
            xmin = a + (-B + np.sqrt(radical)) / (3 * A)
        except ArithmeticError:
            return None
    if not np.isfinite(xmin):
        return None
    return xmin

Instances