How to use the raytracing.abcd.ImagingPath function in raytracing

width=0.1, fc='g', ec='g',
                head_length=arrowHeight, head_width=arrowWidth,
                length_includes_head=True)
            axes.arrow(position, -size-arrowSize, 0, arrowSize,
                width=0.1, fc='g', ec='g',
                head_length=arrowHeight, head_width=arrowWidth,
                length_includes_head=True)


""" Synonym of Matrix: Element 

We can use a mathematical language (Matrix) or optics terms (Element)
"""
Element = Matrix
Group = MatrixGroup
OpticalPath = ImagingPath

def drawBeamTrace(self, axes, beam):
        """ Draw beam trace corresponding to input beam 
        Because the laser beam diffracts through space, we cannot
        simply propagate the beam over large distances and trace it
        (as opposed to rays, where we can). We must split Space() 
        elements into sub elements to watch the beam size expand.
        
        We arbitrarily split Space() elements into 100 sub elements
        before plotting.
        """

        highResolution = ImagingPath()
        for element in self.elements:
            if isinstance(element, Space):
                for i in range(100):
                    highResolution.append(Space(d=element.L/100, 
                                                n=element.frontIndex))
            else:
                highResolution.append(element)


        beamTrace = highResolution.trace(beam)
        (x, y) = self.rearrangeBeamTraceForPlotting(beamTrace)
        axes.plot(x, y, 'r', linewidth=1)
        axes.plot(x, [-v for v in y], 'r', linewidth=1)

def ImagingPath(self):
        return ImagingPath(elements=self.elements, label=self.label)

self.fanNumber = 9         # number of rays in fan
        self.rayNumber = 3         # number of points on object

        # Constants when calculating field stop
        self.precision = 0.001
        self.maxHeight = 10000.0

        # Display properties
        self.showObject = True
        self.showImages = True
        self.showEntrancePupil = True
        self.showElementLabels = True
        self.showPointsOfInterest = True
        self.showPointsOfInterestLabels = True
        self.showPlanesAcrossPointsOfInterest = True
        super(ImagingPath, self).__init__(elements=elements, label=label)