code: def proto_0203(theABF):
      
      abf=ABF(theABF)
      abf.log.info("analyzing as a fast IV")
      plot=ABFplot(abf)
      plot.title=""
      m1,m2=.7,1
      plt.figure(figsize=(SQUARESIZE,SQUARESIZE/2))
  
      plt.subplot(121)
      plot.figure_sweeps()
      plt.axvspan(m1,m2,color='r',ec=None,alpha=.1)
  
      plt.subplot(122)
      plt.grid(alpha=.5)
      Xs=np.arange(abf.sweeps)*5-110
      Ys=[]
      for sweep in range(abf.sweeps):
          abf.setsweep(sweep)
          Ys.append(abf.average(m1,m2))
      plt.plot(Xs,Ys,'.-',ms=10)
      plt.axvline(-70,color='r',ls='--',lw=2,alpha=.5)
      plt.axhline(0,color='r',ls='--',lw=2,alpha=.5)
      plt.margins(.1,.1)
      plt.xlabel("membrane potential (mV)")
  
      # save it
      plt.tight_layout()
      frameAndSave(abf,"fast IV")
      plt.close('all')
docs: protocol: vast IV.