title: Error: "Hit <Return> to see next plot: " in r
body: <p>I have the following code</p>
  
  <pre><code>frame()
  Y = read.table("Yfile.txt",header=T,row.names=NULL,sep='')
  X =  read.table("Xfile.txt",header=F,sep='')
  
  plot(Y$V1~X$V1,pch=20,xlim=c(0,27))
  par(new=T)
  plot(Y$V1~X$V2,pch=20,xlim=c(0,27),col='red')
  par(new=T)
  plot(Y$V1~Y$V3,pch=20,xlim=c(0,27),col='blue')
  par(new=T)
  </code></pre>
  
  <p>All is well and I get the 3 graphs on the same plot. However, when I want to divide X$V1, X$V2 and X$V3 to normalise the data such that</p>
  
  <pre><code>plot(Y$V1~X$V1/Y$V2,pch=20,xlim=c(0,27))
  par(new=T)
  plot(Y$V1~X$V2/Y$V2,pch=20,xlim=c(0,27),col='red')
  par(new=T)
  plot(Y$V1~Y$V3/Y$V2,pch=20,xlim=c(0,27),col='blue')
  par(new=T) 
  </code></pre>
  
  <p>I get the message</p>
  
  <blockquote>
    <p>Hit Return to see next plot: </p>
  </blockquote>
  
  <p>and the graphs just won't show in the same plot. Could anybody tell me what is happening and how to solve it?</p>