title: cannot open file 'Rplots.pdf' using rapache
body: <p>I am trying to generate a pie chart on my browser using rApache </p>
  
  <p>my R code is this</p>
  
  <pre><code>library(MASS)                  
  school = painters$School  
  school.freq = table(school)
  pie(school.freq)
  </code></pre>
  
  <p>when i run this on browser ... i am getting this error</p>
  
  <blockquote>
    <p><b>rApache</b> has something to tell you. View source and read the
    HTML comments at the end.</p>Error in function (file =
    ifelse(onefile, "Rplots.pdf", "Rplot%03d.pdf"),  :   cannot open file
    'Rplots.pdf'</p>
  </blockquote>
  
  <p>any idea why i am getting this error?</p>