title: In DataTable, how to sort a column by partial value?
body: <p>I am using DataTables, a Table plug-in for jQuery, as a tool on my web design. But I encounter a problem since I would like to sort a column by partial value.
  For example, there is a column named "Speaker", with values "Prof. Lin", "Dr. Yu", "Prof. Chen", and so on. When sorting the column, the order will be: <br>
  <br>
  1."Dr. Yu" <br>
  2."Prof. Chen" <br>
  3."Prof. Lin". <br>
  <br>
  I would like to sort by their first name rather than the first letter, which means ordering as: <br>
  <br>
  1."Prof. Chen" <br>
  2."Prof. Lin" <br>
  3."Dr. Yu".<br>
  <br>
  Another example is a column "Average(5% bias)" with values "78.0 (-2.5~2.5)", "90.5 (-1.5~1.5)", "130.0 (-3.0~3.0)", and so on. When sorting the column, the order will be: <br>
  <br>
  1."130.0 (-3.0~3.0)" <br>
  2."78.0 (-2.5~2.5)" <br>
  3."90.5 (-1.5~1.5)". <br>
  <br>
  I would like to sort by their average value rather than the first letter (DataTable thinks the column values are string rather than float), which means ordering as: <br>
  <br>
  1."78.0 (-2.5~2.5)" <br>
  2."90.5 (-1.5~1.5)" <br>
  3."130.0 (-3.0~3.0)".<br>
  <br> 
  <br>
  In my database, there are two columns to store the data, like "title" and "forst_name", "average" and "bias". So it is easy to separate as two parts in a <code>&lt;td&gt;&lt;/td&gt;</code> tag.<br>
  Is it possible to sort a column by partial value using DataTables?</p>