CFLib.org – Common Function Library Project

VarianceSamp(values)

Last updated September 7, 2001

author

Rob Brooks-Bilson

Version: 1 | Requires: CF5 | Library: MathLib

Description:
Returns the sample variance for a set of numeric values. Variance is a measure of how spread out a distribution of data is. This method is used when you have values representing a population sample.

Return Values:
Returns a numeric value.

Example:

<CFSET Values="1,2,3,4,5,6,7,8,9,10"> 

  <CFOUTPUT>
  Given <CFIF IsArray(Values)>{#ArrayToList(Values)#}<CFELSE>{#Values#}</CFIF><BR>
  The variance for the sample is #VarianceSamp(values)#
  </CFOUTPUT>

Parameters:

Name Description Required
values Comma delimited list or one dimensional array of numeric values. Yes

Full UDF Source:

/**
 * Returns the sample variance for a set of numeric values.
 * 
 * @param values 	 Comma delimited list or one dimensional array of numeric values. 
 * @return Returns a numeric value. 
 * @author Rob Brooks-Bilson (rbils@amkor.com) 
 * @version 1.0, September 7, 2001 
 */
function VarianceSamp(values)
{
  Var MyArray = 0;
  Var NumValues = 0;
  Var xBar = 0;
  Var SumxBar = 0;  
  Var i=0;
  if (IsArray(values)){
     MyArray = values;
    }
  else {
     MyArray = ListToArray(values);
    }    
  NumValues = ArrayLen(MyArray);
  xBar = ArrayAvg(MyArray);
  for (i=1; i LTE NumValues; i=i+1) {
    SumxBar = SumxBar + (MyArray[i] - xBar)*(MyArray[i] - xBar);
    }
  Return SumxBar/(NumValues-1);
}
blog comments powered by Disqus

Search CFLib.org


Latest Additions

Kevin Cotton added
date2ExcelDate
May 5, 2016

Raymond Camden added
CapFirst
April 25, 2016

Chris Wigginton added
loremIpsum
January 18, 2016

Gary Stanton added
calculateArrival...
November 19, 2015

Sebastiaan Naafs - van Dijk added
getDaysInQuarter
November 13, 2015

Created by Raymond Camden / Design by Justin Johnson