title: retrieve row and column name of particular cell in R
body: <p>So if I have a data frame that looks like: </p>
  
  <pre><code>             A     B      C  
    rowname1   4.5   4      3.2
    rowname2   3     23     9
  </code></pre>
  
  <p>How do I get R to give me the name(s) of the row/columns that contain a particular number?</p>
  
  <p>i.e. if I give the value 3, it gives back </p>
  
  <pre><code> rowname2,A
  </code></pre>