importfunctoolsimportmatplotlib.pyplotaspltimportnumpyasnpfrommatplotlib.patchesimportRectangle# A class that will regenerate a fractal set as we zoom in, so that you# can actually see the increasing detail.  A box in the left panel will show# the area to which we are zoomed.classMandelbrotDisplay:def__init__(self,h=500,w=500,niter=50,radius=2.,power=2):self.height=hself.width=wself.niter=niterself.radius=radiusself.power=powerdefcompute_image(self,xlim,ylim):self.x=np.linspace(*xlim,self.width)self.y=np.linspace(*ylim,self.height).reshape(-1,1)c=self.x+1.0j*self.ythreshold_time=np.zeros((self.height,self.width))z=np.zeros(threshold_time.shape,dtype=complex)mask=np.ones(threshold_time.shape,dtype=bool)foriinrange(self.niter):z[mask]=z[mask]**self.power+c[mask]mask=(np.abs(z)<self.radius)threshold_time+=maskreturnthreshold_timedefax_update(self,ax):ax.set_autoscale_on(False)# Otherwise, infinite loop# Get the number of points from the number of pixels in the windowself.width,self.height=ax.patch.get_window_extent().size.round().astype(int)# Update the image object with our new data and extentax.images[-1].set(data=self.compute_image(ax.get_xlim(),ax.get_ylim()),extent=(*ax.get_xlim(),*ax.get_ylim()))ax.figure.canvas.draw_idle()md=MandelbrotDisplay()fig1,(ax_full,ax_zoom)=plt.subplots(1,2)ax_zoom.imshow([[0]],origin="lower")# Empty initial image.ax_zoom.set_title("Zoom here")rect=Rectangle([0,0],0,0,facecolor="none",edgecolor="black",linewidth=1.0)ax_full.add_patch(rect)defupdate_rect(rect,ax):# Let the rectangle track the bounds of the zoom axes.xlo,xhi=ax.get_xlim()ylo,yhi=ax.get_ylim()rect.set_bounds((xlo,ylo,xhi-xlo,yhi-ylo))ax.figure.canvas.draw_idle()# Connect for changing the view limits.ax_zoom.callbacks.connect("xlim_changed",functools.partial(update_rect,rect))ax_zoom.callbacks.connect("ylim_changed",functools.partial(update_rect,rect))ax_zoom.callbacks.connect("xlim_changed",md.ax_update)ax_zoom.callbacks.connect("ylim_changed",md.ax_update)# Initialize: trigger image computation by setting view limits; set colormap limits;# copy image to full view.ax_zoom.set(xlim=(-2,.5),ylim=(-1.25,1.25))im=ax_zoom.images[0]ax_zoom.images[0].set(clim=(im.get_array().min(),im.get_array().max()))ax_full.imshow(im.get_array(),extent=im.get_extent(),origin="lower")plt.show()

DownloadJupyternotebook:viewlims.ipynb

DownloadPythonsourcecode:viewlims.py

Downloadzipped:viewlims.zip