def nearest_intersection_idx ( a , b ) : # Difference in the two y-value sets difference = a - b # Determine the point just before the intersection of the lines # Will return multiple points for multiple intersections sign_change_idx , = np . nonzero ( np . diff ( np . sign ( difference ) ) ) return sign_change_idx
python intersection of lines slope intercept
Determine the index of the point just before two lines with common x values .
def nearest_intersection_idx(a, b):
    """Determine the index of the point just before two lines with common x values.

    Parameters
    ----------
    a : array-like
        1-dimensional array of y-values for line 1
    b : array-like
        1-dimensional array of y-values for line 2

    Returns
    -------
        An array of indexes representing the index of the values
        just before the intersection(s) of the two lines.

    """
    # Difference in the two y-value sets
    difference = a - b

    # Determine the point just before the intersection of the lines
    # Will return multiple points for multiple intersections
    sign_change_idx, = np.nonzero(np.diff(np.sign(difference)))

    return sign_change_idx