title: Correlation heatmap
body: <p>I want to represent correlation matrix using a heatmap. There is something called <a href="http://www.sthda.com/english/wiki/visualize-correlation-matrix-using-correlogram" rel="noreferrer">correlogram</a> in R, but I don't think there's such a thing in Python.</p>
  
  <p>How can I do this? The values go from -1 to 1, for example:</p>
  
  <pre><code>[[ 1.          0.00279981  0.95173379  0.02486161 -0.00324926 -0.00432099]
   [ 0.00279981  1.          0.17728303  0.64425774  0.30735071  0.37379443]
   [ 0.95173379  0.17728303  1.          0.27072266  0.02549031  0.03324756]
   [ 0.02486161  0.64425774  0.27072266  1.          0.18336236  0.18913512]
   [-0.00324926  0.30735071  0.02549031  0.18336236  1.          0.77678274]
   [-0.00432099  0.37379443  0.03324756  0.18913512  0.77678274  1.        ]]
  </code></pre>
  
  <p>I was able to produce the following heatmap based on another <a href="https://stackoverflow.com/questions/33282368/plotting-a-2d-heatmap-with-matplotlib">question</a>, but the problem is that my values get 'cut' at 0, so I would like to have a map which goes from blue(-1) to red(1), or something like that, but here values below 0 are not presented in an adequate way.</p>
  
  <p><a href="https://i.stack.imgur.com/GSSDb.png" rel="noreferrer"><img src="https://i.stack.imgur.com/GSSDb.png" alt="enter image description here"></a></p>
  
  <p>Here's the code for that:</p>
  
  <pre><code>plt.imshow(correlation_matrix,cmap='hot',interpolation='nearest')
  </code></pre>