title: How do I change the size of the points based on the value of the column using ggplot?
body: <p>Using ggplot on rstudio, I am trying to change the size of the point of my scatter plot based on the log of the pvalue column. This is how my matrix looks like.</p>
  
  <pre><code>head(BDpvalue)
              id           t-value               pvalue    mean.f    mean.m          Gene Chromosome
  1 ILMN_1212619   3.0512842692996  0.00938046962249251  85.40076  80.02744        Mfap3l          8
  2 ILMN_1212693  3.40887110529531  0.00452088152864021  87.28189  82.89533         Snx33          9
  3 ILMN_1213324 -4.54750670298688 0.000414140589714275  82.68924  88.81421        Zfp961          8
  4 ILMN_1213848 -3.63180275429357  0.00246745595956587 421.61780 469.51845      Itgb1bp1         12
  5 ILMN_1213961  2.97573716869553  0.00960659647288939  82.01748  78.44721         Copg2          6
  6 ILMN_1214482 -4.23666060706341 0.000813240203181102 136.55021 153.34681 2700081O15Rik         19
  </code></pre>
  
  <p>></p>
  
  <p>The code to change the size based on the log of the pvalue column seems correct to me, but for some reason I am not seeing a change in the graph, this is the code that I used.</p>
  
  <pre><code>ggplot(BDpvalue, aes(x=(log(mean.m,10)+log(mean.f,10))/2,
  y= log(mean.f/mean.m,10),color=Chromosome) + geom_point(aes(size=(-log(pvalue,10))))
  </code></pre>