CFLib.org – Common Function Library Project

Description:
Returns the median (middle) value for a set of numberic values. The values can come from a list or a one dimensional array.

Return Values:
Returns a simple value.

Example:

<CFSET Values1="1,2,3,4,5,6,7,8,9,10">
<CFSET Values2="1,2,3,4,5,6,7,8,9,10,11">

<CFOUTPUT>
Given Values1 = <CFIF IsArray(Values1)>{#ArrayToList(Values1)#}<CFELSE>{#Values1#}</CFIF><BR>
Given Values2 = <CFIF IsArray(Values2)>{#ArrayToList(Values2)#}<CFELSE>{#Values2#}</CFIF><BR>
The median of Values1 is #Median(values1)#<BR>
The median of Values2 is #Median(values2)#<BR>
</CFOUTPUT>

Parameters:

Full UDF Source:

/**
 * Returns the median (middle) value for a set of numberic values.
 * 
 * @param values      Comma delimited list or one dimensional array of numeric values. 
 * @return Returns a simple value. 
 * @author Rob Brooks-Bilson (rbils@amkor.com) 
 * @version 1.0, July 18, 2001 
 */
function Median(values)
{
  Var x = 0;
  Var NumberOfElements = 0;
  Var LeftCenterPosition = 0;
  Var RightCenterPosition = 0;
  Var MyArray = 0;
  if (IsArray(values)){
     MyArray = values;
    }
  else {
     MyArray = ListToArray(values);
    }
  ArraySort(MyArray, "numeric");
  x = ArrayToList(MyArray);
  NumberOfElements = ListLen(x);
  if ((NumberOfElements MOD 2) EQ 0) {
      LeftCenterPosition = ListGetAt(x, (Int(NumberOfElements/2)), ",");
      RightCenterPosition = ListGetAt(x, (Int(NumberOfElements/2)+1), ",");
      Return (LeftCenterPosition + RightCenterPosition)/2;
    }
  else {
      Return ListGetAt(x, Int(NumberOfElements/2)+1, ",");
    }
}