title: Filter values in data frame
body: <p>Basically, I have a gene dataset in which the rows are genes and columns are sequential time points of protein folding. I need a function to filter genes of a certain threshold value from others across the entire data set, not just for certain vectors. For example:</p>
  
  <pre><code>          alpha98 alpha105 alpha112 alpha119
  YAL002W      0.22     0.58    -0.36     0.13
  YAL003W      0.05     0.55    -0.08     0.33
  </code></pre>
  
  <p>Any help would be great.</p>