Return x,y values evaluated with a given pixel step.

def linspace_pix(self, start=None, stop=None, pixel_step=1, y_vs_x=False):
        """Return x,y values evaluated with a given pixel step."""
        return CCDLine.linspace_pix(self, start=start, stop=stop,
                                    pixel_step=pixel_step, y_vs_x=y_vs_x)