Stretch or shrink detector (DOM positions) by a given factor.

def rescale(self, factor, origin=(0, 0, 0)):
        """Stretch or shrink detector (DOM positions) by a given factor."""
        pmts = self.pmts
        for dom_id in self.dom_ids:
            mask = pmts.dom_id == dom_id
            pos_x = pmts[mask].pos_x
            pos_y = pmts[mask].pos_y
            pos_z = pmts[mask].pos_z
            pmts.pos_x[mask] = (pos_x - origin[0]) * factor
            pmts.pos_y[mask] = (pos_y - origin[1]) * factor
            pmts.pos_z[mask] = (pos_z - origin[2]) * factor
        self.reset_caches()