CFLib.org – Common Function Library Project

Description:
Function which returns the value of a certain quantile from a list of numeric values. Similar to the quantile(matrix,alpha) function in ms excel.

Return Values:
Returns a number.

Example:

<cfset quantile = hyGetQuantile("30","1,2,3,4")>
<cfoutput>#quantile#</cfoutput>

Parameters:

Full UDF Source:

/**
 * Function which returns the value of a certain quantile from a list of numeric values.
 * Rewritten by Raymond Camden to include VAR statements.
 * 
 * @param qtil      Threshold value for the quantile, numeric between 1 and 100 (Required)
 * @param range      Comma delimited list of numeric values (Required)
 * @return Returns a number. 
 * @author Ralf Guttmann (ralf.guttmann@hyperspace.de) 
 * @version 1, July 13, 2006 
 */
function hyQuantile(qtil, range) {
    var rangeArr = ListToArray(range);
    var hyqtil = "";
     var nrofelms = "";
     var nrofsteps = "";
    var percpos = "";
    var percpos1 = "";
     var percpos2 = "";
    var rP1 = "";
    var rP2 = "";
    var deltarp = "";
    var wfactor = "";
    var deltarp_v = "";

    qtil = qtil * 0.01;
    arraySort(rangeArr, "numeric");
  
    nrofelms = arrayLen(rangeArr);
    nrofsteps = qtil * (nrofelms - 1);
    
    if(int(nrofsteps) eq nrofsteps) {
        percpos = nrofsteps + 1;
        hyqtil = rangeArr[percpos];
    } else {
        percpos1 = Int(nrofsteps) + 1;
        percpos2 = percpos1 + 1;
        rP1 = rangeArr[percpos1];
        rP2 = rangeArr[percpos2];
        deltarp = rP2 - rP1;
        wfactor = nrofsteps - (Int(nrofsteps));
        deltarp_v = deltarp * wfactor;
        hyqtil = rP1 + deltarp_v;
    }
    return hyqtil;
}