title: Inconsistent results with plot in R
body: <p>I'm experimenting with plot in R and I'm trying to understand why it has the following behaviour. </p>
  
  <p>I send a table into the plot function and it gives me a very nice variwidth graph which is quite insightful. However, after I reorder the columns of the table and send it to plot again, I get an odd scatter plot.  What has happened in the re-ordering and how can I avoid this?</p>
  
  <pre><code>smoke &lt;- matrix(c(51,43,22,92,28,21,68,22,9),ncol=3,byrow=TRUE)
  colnames(smoke) &lt;- c("High","Low","Middle")
  rownames(smoke) &lt;- c("current","former","never")
  smoke &lt;- as.table(smoke)
  plot(smoke)  # This gives me a variwidth plot
  smoke = smoke[,c("Low", "Middle", "High")] # I reorder the columns
  plot(smoke)  # This gives me a weird scatter plot
  </code></pre>