CFLib.org – Common Function Library Project

Description:
Rounds a number to a specified number of significant digits.

Return Values:
Returns a numeric value.

Example:

<CFSET iOrigNo=10.5660>
<cfoutput>
Original=#iOrigNo#<br> 
After RoungSigFig=#RoundSigFig(iOrigNo, 4)#
</cfoutput>

Parameters:

Full UDF Source:

/**
 * Rounds a number to a specified number of significant digits.
 * 
 * @param fInput      Number to round. (Required)
 * @param iDigits      Number of significant digits to return. (Required)
 * @return Returns a numeric value. 
 * @author jason snyder (jason.snyder@trw.com) 
 * @version 2, October 24, 2003 
 */
function RoundSigFig(fInput, iDigits) 
{
  //Local Variables
  var iLog = 0;
  var iTemp = 0;
  var fReturn = 0;

  //Execution
  if (fInput NEQ 0) { //If not zero round to significant digits.
    iLog=Int(Log10(Sgn(fInput)*fInput+0.0));
    iTemp=Round(fInput / (10^(iLog-iDigits+1)));
    //return(Log10(fInput+0.0)); //Debugging
    fReturn=evaluate(iTemp*(10^(iLog-iDigits+1)));
  } //End (Round to significant digits.)
  Return(fReturn);
} //End (RSigFig)