title: How to repeat eficiently part of plot for succesive plots in PyPlot or Matplotlib?
body: <p>I am making a succesion of plots for an animation that consists of a colormap that changes and has a diagram of a neuron over it that is static.
  The heatmap is very easy to plot for the computer, and is fast, but the diagram of the neuron is quite laborious ( some 4000 data points ) and takes a lot of to repeat it for every frame. So I thought, can it be possible to only redraw the heatmap?</p>
  <p>I am using PyPlot through Julia, so my code looks like this:</p>
  <pre><code>for t=1:801
      f=figure(figsize=(4,3))
      imshow(lfp3[t,:,:], extent=[-700,700,-400,1200], origin=&quot;lower&quot;)
      for l in cel2
          plot(l[:,1], l[:,2], marker=&quot;None&quot;, linewidth=1)
      end
      nstring=lpad(t, 4, &quot;0&quot;)
      nom=&quot;tubuela-$nstring&quot;*&quot;.png&quot;
      savefig(nom,dpi=72)
      close()
      if mod(t,50)==0
          println(&quot;listos $t&quot;)
      end
  end
  </code></pre>