code: function(num, sig) {
          var fig = 0;
          if (sig > 0) {
              fig = parseFloat(num.toPrecision(sig));
          }
          return fig;
      }
docs: APIFunction: limitSigDigs
  Limit the number of significant digits on a float.
  
  Parameters:
  num - {Float}
  sig - {Integer}
  
  Returns:
  {Float} The number, rounded to the specified number of significant
  digits.