function preMain() {
     
    setDefaultBarFgColor(Color.yellow , 0); // %K
    setDefaultBarFgColor(Color.cyan , 1); // %D
    
}

function main(inputLength, inputSmoothingK, inputSmoothingD) {
    if(inputLength == null)
        inputLength = 15;
    if(inputSmoothingK == null)
        inputSmoothingK = 3;
    if(inputSmoothingD == null)
        inputSmoothingD = 5;
  
    var nOffset = 0;
    var nLength = inputLength;
    var nSmoothingK = inputSmoothingK;
    var nSmoothingD = inputSmoothingD;
    var d_wma_k = 0.0;
    var d_wma_d = 0.0;
   
       
    d_wma_k = GetK(nLength , nSmoothingK , nOffset);
    d_wma_d = GetD(nLength , nSmoothingK , nSmoothingD);
    
    return new Array(d_wma_k , d_wma_d);
        
}

function GetK(nLength , nSmoothingK , nOffset){
    var percentK;
    var close = 0.0;
    var ll, hh;
    var i;
    var sum = 0;
    var nDO;
 
    for(i = 0; i < nSmoothingK; i++) {
        nDO = -i + nOffset;

        close = getValue("Close", nDO);
        if(close == null) {
            return null;
        }

        ll = callFunction("/library/StochasticLL.efs", "main" , nDO, -nLength);
        
        if(ll == null) {
            return null;
        }
        
        hh = callFunction("/library/StochasticHH.efs", "main" , nDO, -nLength);
        
        if(hh == null) {
            return null;
        }
        
        
        percentK = ((close - ll) / (hh - ll)) * 100;
        sum += percentK * (nSmoothingK - i);
        
    }

    sum /= (nSmoothingK * (nSmoothingK + 1) / 2);
    
    return sum;
}

function GetD(nLength , nSmoothingK , nSmoothingD){
    var i;
    var ret = 0.0
    var sum = 0.0;
    
    for(i = 0; i < nSmoothingD; i++) {
        ret = GetK(nLength , nSmoothingK , -i);
        if(ret == null)
           return -1.0;
        sum += ret * (nSmoothingD - i);
    }
    
    sum /= (nSmoothingD * (nSmoothingD + 1) / 2);
    return sum;
}