LSMA Channel

[JayF]

File Name: LSMA_Channel.efs

Description:
Calculates the Least Square Moving Average (LSMA)
off the high and also off the low to create a channel.

Formula Parameters:
HiLength - Defines the length of the LSMA off the High. Default is 25.
LoLength - Defines the length of the LSMA off the Low. Default is 25.
HiOffset - Defines how offset the LSMA(High) is. Default is 0.
LoOffset - Defines how offset the LSMA(Low) is. Default is 0.
HiColor - Defines the color of the LSMA(High). Default is blue.
LoColor - Defines the color of the LSMA(Low). Default is red.

Download File:
LSMA_Channel.efs



EFS Code:

/*************************
Copyright © eSignal, 2003
**************************
Description: Calculates the Least Square Moving Average (LSMA)
off the high and also off the low to create a channel.

Version Control:

*/



function preMain()
{
    setPriceStudy(true);    
    setStudyTitle("LSMA Channel");
    setCursorLabelName("LSMA Hi",0);
    setCursorLabelName("LSMA Lo",1);
    setDefaultBarThickness(2,0);
    setDefaultBarThickness(2,1);
    
    var fp1 = new FunctionParameter("HiLength", FunctionParameter.NUMBER);
    fp1.setName("Length of LSMA(High)");
    fp1.setDefault(25);
    
    var fp2 = new FunctionParameter("LoLength", FunctionParameter.NUMBER);
    fp2.setName("Length of LSMA(Low)");
    fp2.setDefault(25);
    
    var fp3 = new FunctionParameter("HiOffset", FunctionParameter.NUMBER);
    fp3.setName("Offset of LSMA(High)");
    fp3.setDefault(0);
    
    var fp4 = new FunctionParameter("LoOffset", FunctionParameter.NUMBER);
    fp4.setName("Offset of LSMA(Low)");
    fp4.setDefault(0);
    
    var fp5 = new FunctionParameter("HiColor", FunctionParameter.COLOR);
    fp5.setName("Color of LSMA(High)");
    fp5.setDefault(Color.blue);
    
    var fp6 = new FunctionParameter("LoColor", FunctionParameter.COLOR);
    fp6.setName("Color of LSMA(Low)");
    fp6.setDefault(Color.red);
}

var aHigh = null;
var aLow = null;
var aHiLSMA = null;
var aLoLSMA = null;
var vInit = false;
var LSMA_Array = new Array();

function main(HiLength,LoLength,HiOffset,LoOffset,HiColor,LoColor)
{

    if (vInit == false) {
        aHigh = new Array(HiLength);
        aLow = new Array(LoLength);
        aHiLSMA = new Array(HiLength);
        aLoLSMA = new Array(LoLength);
        setDefaultBarFgColor(HiColor,0);
        setDefaultBarFgColor(LoColor,1);
        preMain();      
        vInit = true;
    }
    
    vHigh = high();
    vLow = low();
    
    if (vHigh == null) return;
    if (vLow == null) return;
    
    if (getBarState() == BARSTATE_NEWBAR) {
        if (aHigh[HiLength-1] != null) aHigh.pop();
        aHigh.unshift(vHigh);
        if (aLow[LoLength-1] != null) aLow.pop();
        aLow.unshift(vLow);
    }
  
    aHigh[0] = vHigh;
    aLow[0] = vLow;
    
    if (aHigh[HiLength-1] == null || aLow[LoLength-1] == null) return;
    
    // get LSMA values and assign to arrays
    var vHiLSMA = getLSMA(aHigh, HiLength);
    var vLoLSMA = getLSMA(aLow, LoLength);
    
    if (getBarState() == BARSTATE_NEWBAR) {
        if (aHiLSMA[HiLength-1] != null) aHiLSMA.pop();
            aHiLSMA.unshift(vHiLSMA);
        if (aLoLSMA[LoLength-1] != null) aLoLSMA.pop();
            aLoLSMA.unshift(vLoLSMA);
    }
    
    aHiLSMA[0] = vHiLSMA;
    aLoLSMA[0] = vLoLSMA;

    return new Array (aHiLSMA[HiOffset], aLoLSMA[LoOffset]);
}

// ------------------------------------
// Get a LSMA value
function getLSMA(aPrice, nLength) {
    var Num1 = 0.0;
    var Num2 = 0.0;
    var SumBars = nLength * (nLength - 1) * 0.5;
    var SumSqrBars = (nLength - 1) * nLength * (2 * nLength - 1) / 6;
    var SumY = 0.0;
    var Sum1 = 0.0;
    var Sum2 = 0.0;
    var Slope = 0.0;
    var Intercept = 0.0;
    
    for (i = 0; i < nLength; ++i) {
        SumY += aPrice[i];
        Sum1 += i * aPrice[i];
    }
    Sum2 = SumBars * SumY;
    Num1 = nLength * Sum1 - Sum2;
    Num2 = SumBars * SumBars - nLength * SumSqrBars;
    if (Num2 != 0) Slope = Num1 / Num2;
    Intercept = (SumY - Slope * SumBars) / nLength;
    var LinearRegValue = Intercept + Slope * (nLength - 1);

    return LinearRegValue;
}