title: Prevent cex from scaling with the correlation coefficient in chart.Correlation()
body: <p>I'm trying to plot a huge matrix of correlation coefficients, and currently, my plot looks like this:
  <img src="https://i.stack.imgur.com/cZLfl.png" alt="Notice that some cells are missing correlation coefficients"></p>
  
  <p>Notice that some cells are missing correlation coefficients (ignore for now that lack of symmetry of the plot, unless you happen know why that's the case, too). I believe that the values are not, in fact, missing, but simply too small to appear, because they are scaled by the value of their correlation coefficient.</p>
  
  <p>Looking at the documentation for chart.Correlation(), I was able to find a function from which much of the content of chart.Correlation() was modeled:</p>
  
  <pre><code>panel.cor &lt;- function(x, y, digits=2, prefix="", cex.cor)
  {
      usr &lt;- par("usr"); on.exit(par(usr))
      par(usr = c(0, 1, 0, 1))
      r &lt;- abs(cor(x, y))
      txt &lt;- format(c(r, 0.123456789), digits=digits)[1]
      txt &lt;- paste(prefix, txt, sep="")
      if(missing(cex.cor)) cex &lt;- 0.8/strwidth(txt)    
      test &lt;- cor.test(x,y)
      # borrowed from printCoefmat
      Signif &lt;- symnum(test$p.value, corr = FALSE, na = FALSE,
                    cutpoints = c(0, 0.001, 0.01, 0.05, 0.1, 1),
                    symbols = c("***", "**", "*", ".", " "))
  
      text(0.5, 0.5, txt, cex = cex * r)
      text(.8, .8, Signif, cex=cex, col=2)
  }
  pairs(USJudgeRatings[,c(2:3,6,1,7)], lower.panel=panel.smooth, upper.panel=panel.cor)
  </code></pre>
  
  <p>If I change:</p>
  
  <pre><code>text(0.5, 0.5, txt, cex = cex * r)
  </code></pre>
  
  <p>To:</p>
  
  <pre><code>text(0.5, 0.5, txt, cex = 0.8)
  </code></pre>
  
  <p>I get roughly the effect I'm looking for. The problem is that I have no idea how to change this parameter using chart.Correlation() itself. Does issue this make sense?</p>