title: Having error to write a plot title in global variable in R
body: <p>Here is my program: </p>
  
  <pre><code>sim.clt &lt;- function(n, ran.func,stat.func,hist.titl, simsize, ...) 
   {
  
   xbars &lt;- numeric(simsize)
  for(i in seq_len(simsize)) {
  FUN &lt;- match.fun(ran.func)
  x &lt;- FUN(n = n, ...)
  f1&lt;-match.fun(stat.func)
  xbars[i] &lt;- f1(x)
  }
  ## plot
  op &lt;- par(mfrow=c(2,1))
  on.exit(op)
  hist(xbars)
  hist.titl&lt;-title("hist")
  qqnorm(xbars,main="Q-Q plot for distribution")
  xbars
  }
  
  sim.out&lt;-sim.clt(n=20,stat.func="mean",ran.func="rexp",hist.titl="histo",simsize=5000)
  shapiro.test(sim.out)
  </code></pre>
  
  <p>I would like to add an option to <code>sim.out</code> called <code>hist.titl</code>, but it's not working.</p>
  
  <p>thanks</p>