/****************************************************************************************************
Copyright © eSignal, a division of Interactive Data Corporation. 2006. All rights reserved. 
This sample eSignal Formula Script (EFS) may be modified and saved under a new 
filename; however, eSignal is no longer responsible for the functionality once modified.
eSignal reserves the right to modify and overwrite this EFS file with each new release.
*****************************************************************************************************/

function preMain() {
    setPriceStudy(true);
    
    /* Set the title that will appear in the study pane */
    setStudyTitle("Keltner");

    /* Set the label that will appear in the cursor window */
    setCursorLabelName("K-Upper", 0);
    setCursorLabelName("K-Basis", 1);
    setCursorLabelName("K-Lower", 2);

    setDefaultBarFgColor(Color.blue, 0); // upper
	setDefaultBarFgColor(Color.red, 1); // basis
	setDefaultBarFgColor(Color.blue, 2); // lower
	
	var fp1 = new FunctionParameter("nInputLength", FunctionParameter.NUMBER);
        fp1.setName("Length");
        fp1.setLowerLimit(1);
        fp1.setDefault(10);
}

var xKeltner = null;

function main(nInputLength) {
    if (xKeltner == null) xKeltner = efsInternal("calcKeltner", nInputLength);
    
    var nKupper = getSeries(xKeltner, 0);
    var nKbasis = getSeries(xKeltner, 1);
    var nKlower = getSeries(xKeltner, 2);

    return new Array(nKupper, nKbasis, nKlower);
}


var xHLC3 = null;

function calcKeltner(n) {
	if(close(-n) == null) return;

    if (xHLC3 == null) xHLC3 = efsInternal("calcHLC3");
    
	var vHLC3 = 0;
	var vHminL = 0;
	for(var i = 0; i < n; i++) {
		vHLC3 += xHLC3.getValue(-i);
		vHminL += high(-i) - low(-i);
	}

	vHLC3 /= n;
	vHminL /= n;

	return new Array(vHLC3 + vHminL, vHLC3, vHLC3 - vHminL);
}

function calcHLC3() {
    return (high(0) + low(0) + close(0)) / 3;
}