title: Matplotlib create real time animated graph
body: <p>I am having a hard time setting up my code to create a real time animated graph, my code is graphing after the data is being collected, not showing every iteration. My script runs a regression function then stores in a file, then I access the files and plot them, here is what I have, what do I need to move around or change to have it graph real time? I tried moving the plot functions inside the <code>for</code> loop but that didn't work, any suggestions?</p>
  
  <pre><code> fig = plt.figure()
   ax1 = fig.add_subplot(1,1,1)
  
   num = 10 
   for idx in range(1,num):
      c,e = Regr_magic()
          with open("CK_output.txt",'a') as CK:
              CK.write("{0},{1}\n".format(idx,c))
          with open("error_output.txt",'a') as E:
              E.write("{0},{1}\n".format(idx,e))
  
  
  
      def animate(i):
          pull = open('error_output.txt','r').read()
          data = pull.split('\n')
          xar = []
          yar = []
  
          for each in data:
              if len(each)&gt;1:
                  x,y = each.split(',')
                  xar.append(float(x))
                  yar.append(float(y))
              ax1.plot(xar, yar)
      ani = animation.FuncAnimation(fig, animate, interval=1000)
      plt.show()
  </code></pre>
  
  <p>FYI, data files contain the following, the iteration number and Ck value or error, so they look like this</p>
  
  <pre><code>1,.0554
  2,.0422
  3,.0553
  4,.0742
  5,.0232
  </code></pre>