def tolerance_slope_window(base_x, base_y, point_x, point_y, tol):
    """ Compute slope window for rays to be within tolerance of supplied point

    Computes slope window of 2d cone with base point `(base_x, base_y)` and
    which passes through points `(point_x, point_y-tol)` and `(point_x,
    point_y+tol)`.
    """
    slope_min = (point_y - base_y - tol) / (point_x - base_x)
    slope_max = (point_y - base_y + tol) / (point_x - base_x)

    return slope_min, slope_max