title: python matplotlib the relationship between colormap and vmax/vmin
body: <p>I am new on python matplotlib, i am trying different setting on <code>cmp</code> and <code>vmax</code>,<code>vmin</code></p>
  
  <p>For my understanding if the result higher than <code>vmax</code> ,the result show the end of the colormap(dark) and the result lower then the <code>vmin</code> the result shows the original of the colormap(light) like pic1
  <a href="https://i.stack.imgur.com/52vy4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/52vy4.png" alt="pic1"></a></p>
  
  <p>But when i set the <code>vmax</code> or <code>vmin</code> out of the result,how the color resconding to the result??why it shows like this?</p>
  
  <p>such as when i set the <code>vmin</code> out of the range and the result show the bule but there's no blue in my <code>cmp</code> see pic2
  <a href="https://i.stack.imgur.com/FndI1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FndI1.png" alt="pic2"></a></p>
  
  <p>and when the <code>vmax</code> out of the range the result show the light color,for my understanding the color should be the same as <code>cmp=plt.cm.Greens</code> see pic3
  <a href="https://i.stack.imgur.com/W9WfG.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/W9WfG.png" alt="pic3"></a></p>
  
  <p>i upload the pic.
  Here's my code:</p>
  
  <pre><code>#!/usr/bin/python
  import matplotlib.pyplot as plt
  
  
  num=range(1,100)
  out=[x**2 for x in num]
  plt.figure(figsize=(11, 11))
  
  
  plt.title('Scatter',size=24)
  plt.ylabel('Result',size=24)
  plt.xlabel('Number',size=24)
  plt.axis([0, 110, 0, 11000])
  
  plt.scatter(num,out,s=50,lw=2,c=out,cmap=plt.cm.Greens,marker='o',label='Scatter',vmin=99999)
  plt.show()
  </code></pre>