title: Why the plot is linear when i am plotting an exponential function
body: <p>I expect a curve cause of using exponential function but i get linear plot...
  why this happens?
  I am just going to plot values of V and i expect to be an exponential curve not linear </p>
  
  <pre class="lang-py prettyprint-override"><code>import numpy as np
  import matplotlib.pylab as plt
  
  I=[1,1,0,1,0,1,1,1,0,0]
  V=np.zeros(10)
  counter=0
  
  def eps(s):
      return (s/1.5)*np.exp(1-(s/1.5))
  
  for t in range(10):
      _I= I[:t+1]    
      for counter in range(t+1):
          if _I[counter]==1:
              t_f=counter
              s=t- t_f
              V[t]+=eps(s)
          if V[t]&gt;3:
              V[t-1]=4
              V[t]=-0.065
      print('V[t] in t=',t,'is=',V[t])
  
  plt.figure()
  plt.plot(V)
  plt.show()
  
  
  </code></pre>