def set_range(self, min_val, max_val):
        """Set the range of the colormap to [*min_val*, *max_val*]
        """
        if min_val > max_val:
            max_val, min_val = min_val, max_val
        self.values = (((self.values * 1.0 - self.values.min()) /
                        (self.values.max() - self.values.min()))
                       * (max_val - min_val) + min_val)