Aroon Up

/*********************************Provided By:      eSignal (Copyright c eSignal), a division of Interactive Data     Corporation. 2009. All rights reserved. This sample eSignal     Formula Script (EFS) is for educational purposes only and may be     modified and saved under a new file name.  eSignal is not responsible    for the functionality once modified.  eSignal reserves the right     to modify and overwrite this EFS file with each new release.Description:            AroonUp      Version:            1.0  05/14/2009    Formula Parameters:                     Default:    Length                              14    Notes:    This formula is one of the components of the Aroon and Aroon Oscillator     indicators.    Developed by Tushar Chande in 1995, the Aroon is an indicator system     that can be used to determine whether a stock is trending or not and     how strong the trend is. "Aroon" means "Dawn's Early Light" in Sanskrit     and Chande choose that name for this indicator since it is designed to     reveal the beginning of a new trend.    The Aroon indicator consists of two lines, Aroon(up) and Aroon(down).     The Aroon Oscillator is a single line that is defined as the difference     between Aroon(up) and Aroon(down). All three take a single parameter which     is the number of time periods to use in the calculation. Since Aroon(up) and     Aroon(down) both oscillate between 0 and +100, the Aroon Oscillator ranges     from -100 to +100 with zero serving as the crossover line.    AroonUp indicator is calculated according to formula:    AroonUp = 100 * (Period - PeriodHigh) / Period    where PeriodHigh = Number of bars since highest high of the Period    AroonUp for a given time period is calculated by determining how much time     (on a percentage basis) elapsed between the start of the time period and the point     at which the highest closing price during that time period occurred. When the stock     is setting new highs for the time period, AroonUp will be 100. If the stock has     moved higher every day during the time period, AroonUp will be zero.**********************************/function preMain() {    setStudyTitle("Aroon Up");    setCursorLabelName("ArnUp", 0);    setDefaultBarFgColor(Color.red,1);    var fp1 = new FunctionParameter("nInputPeriod", FunctionParameter.NUMBER);        fp1.setName("Length");        fp1.setLowerLimit(1);        fp1.setDefault(14);}var bInit = null;var AryClose;function main(nInputPeriod){    var vState = getBarState();    if (vState == BARSTATE_ALLBARS || bInit == false){        AryClose = new Array(nInputPeriod);        bInit = true;    }    if (vState == BARSTATE_NEWBAR) {	    AryClose.pop();		AryClose.unshift(high(0));    } else {		AryClose[0] = high(0);    }    if (AryClose[AryClose.length-1] == null) return;    var vIndex = findHighIndex(AryClose);    return ((nInputPeriod-vIndex)/nInputPeriod)*100;}function findHighIndex(AryIn){    var vHighIndex = 0;    var vHigh = 0.0;    vHigh = AryIn[0];    for(var i = 1; i < AryIn.length; i++){        if (vHigh < AryIn[i]) {             vHigh = AryIn[i];            vHighIndex = i;        }    }    return vHighIndex;}