title: R: Convert variable name to string in sapply
body: <p>I have found that to convert a variable name into a string I would use <code>deparse(substitute(x))</code> where <code>x</code> is my variable name.  But what if I want to do this in an sapply function call?</p>
  
  <pre><code>sapply( myDF, function(x) { hist( x, main=VariableNameAsString ) } )
  </code></pre>
  
  <p>When I use <code>deparse(substitute(x))</code>, I get something like <code>X[[1L]]</code> as the title.  I would like to have the actual variable name.  Any help would be appreciated.</p>
  
  <p>David</p>