title: Plotting a 2D array with matplotlib.imshow
body: <p>The <code>np.array</code> that results from this loop has 4383 rows and 6 columns. I have tried without success to use <code>pylab.imshow()</code> from matplotlib(pylab) to display the array. The objective is to creat an image of the array, in wich the colors gradient represent the magnitude of the array values. Each row of the array represents the variation in depth of a lake temperature in each day (4383 days). Thus the objective is to find diferences in lake temperatures in depth and with time. Thank you</p>
  
  <pre><code>TempLake=np.zeros((N+1,Nlayers)) 
  TempLake[0]=T0 
  
  Q=np.zeros(N+1) 
  Q[0]=0.0 
  for i in xrange(N): 
      Q[i+1]=Qn(HSR[i],TD[i],FW[i],TempLake[i][0]) 
      TempLake[i+1]=main_loop(Z,z,Areat0,Areat1,TempLake[i],wind[i],Q[i],Q[i+1]) 
  
  
  im = plt.imshow(tem, cmap='hot') 
  plt.colorbar(im, orientation='horizontal')  
  plt.show() 
  </code></pre>
  
  <p>This is the result: The legend is fine, but the x-axis are inverted and the image doesn´t appear
  <img src="https://i.stack.imgur.com/VGYU1.png" alt="enter image description here"></p>
  
  <p>This is what I need:
  <img src="https://i.stack.imgur.com/NQmZG.png" alt="enter image description here"></p>