title: Control the size of points in an R scatterplot?
body: <p>In R, the <code>plot()</code> function takes a <code>pch</code> argument that controls the appearance of the points in the plot.  I'm making scatterplots with tens of thousands of points and prefer a small, but not too small dot.  Basically, I find <code>pch='.'</code> to be too small, but <code>pch=19</code> to be too fat.  Is there something in the middle or some way to scale the dots down somehow?</p>