title: Plotting 3 cols of pandas dataframe as heatmap
body: <p>I'm almost certain that this is a duplicate, but I'm having trouble finding the answer in a reasonable amount of time.</p>
  
  <p>I have dataframe with the three columns below:</p>
  
  <pre><code>    COLS  FUNCS  FLUFF
  32     1      1    3.24707
  33     1      2   14.89260
  34     1      3   48.60840
  35     1      4   73.68160
  36     2      1    4.19922
  37     2      2   64.89260
  38     2      3   87.91500
  39     2      4   91.01560
  40     4      1   23.58400
  41     4      2   87.89060
  42     4      3   95.38570
  43     4      4   98.33980
  44     8      1   34.47270
  45     8      2   95.43460
  46     8      3   99.04790
  47     8      4   99.80470
  </code></pre>
  
  <p>I want to plot a heat map of these data with COLS on the horizontal axis and FUNCS on the vertical axis with cells that are scaled according to FLUFF.  <strong>I don't want to use seaborn</strong>.  I want to use matplotlib and/or pandas exclusively.</p>
  
  <p>If you also have some insight on how to achieve a logarithmic color scheme, that would also would great.</p>