/********************************************************************
 * Copyright Garth Doverspike  2001
 * frmGMAcc - Acceleration per Bill Williams
 *
 * No warranty expressed or implied on functionality - Use at your own risk
 * If you find a bug please email me
********************************************************************/

function preMain() {
	setStudyTitle("GMACC");
	setCursorLabelName("GMACC");

	/*
	 * Set the properties of the default bar.  These will be the
	 * properties of any bar for which style, color, thickness is
	 * not specificed.
	 */
	setDefaultBarStyle(PS_SOLID);
	
/*
	setStudyMax(100);
	setStudyMin(-100);
*/
	
	
	setDefaultBarFgColor(Color.black);
	setDefaultBarBgColor(Color.white);
	
	setDefaultBarThickness(2);
	
	
	setPlotType(PLOTTYPE_HISTOGRAM);
	
}

/*****
  Variables to remember across iterations to main.
****/

var vLastRet = 0;
var vLastMom = 0;

/*
 * Momentum Acceleration
 */
function main() {
  	
	var vhighs;
	var vlows;
	var vLongLength = 34;
	var vShortLength = 5;
	var vMALength = 5;
	var i;
	var vASum;
	var x;
	var vSymbol;
	var vIsGreen;
	
	var vSum = new Array(5);
	var vShortSum = new Array(5) ;
	
	if ((vSymbol = getSymbol()) == null){
        return;
    }
   
    vDiffMA = 0;
   
    /*
     * We loop on the GMOM to get a MA of it
     */       
    vASum = 0;
    for (x = 0; x < vMALength; x ++){
        
        /* 
         * Get highs and lows for 34 bars for each x
         */
         if (x == 0){
         	vhighs = high (x, -vLongLength);
         	vlows = low (x, -vLongLength);
	 } else {
		vhighs = high (-x, -vLongLength);
         	vlows = low (-x, -vLongLength);
	 }

         /*
          * Check for NULL returns
          */

         if (vhighs == null || vlows == null) {
             return;
         }
         /*
          * Calc the two MA's
          */
         vSum[x] = 0;
         vShortSum[x] = 0;
         for (i = 0; i < vLongLength; i++) {
             vSum[x] += (((vhighs[i] - vlows[i])/2) + vlows[i]);
             if (i == vShortLength - 1){
                vShortSum [x]= vSum[x];
             }
         }
         /*
          * vSum now 34 day MA
          */
         vSum[x] = vSum[x]/vLongLength;
         /*
          * vShortSum = 5 day MA
          */
         vShortSum[x] = vShortSum[x]/vShortLength;
         /*
          * vSum now = MOM
          */      
          vSum[x] = vShortSum[x] - vSum[x]; 
         /* 
          * vASum = Sum of 5 day MOM
          */
         vASum = vASum + vSum[x];
    }
    /*
     * Now 5 day MA of MOM
     */
    vASum = vASum/vMALength;
    /*
     * Now difference between MOM and 5 day MA
     */
    vASum = vSum[0] - vASum;
        
    /*
     * Determine if MOM for this period is green, and set LastMom
     */
     if (vSum[0] < vLastMom){
         vIsGreen = 0;
     } else {
         vIsGreen = 1;
     }
    vLastMom = vSum[0];
    switch (vSymbol){
        case ("$INDU"):
            vASum = vASum/100;
            break;
        case ("$COMPQ"):
            break;
        default:
            break;
    }
    if (vASum < vLastRet){
        setBarFgColor(Color.maroon);
        if (vIsGreen == 0){
            setBarBgColor(Color.red);
        } 
    } else {
        setBarFgColor(Color.green);
        if (vIsGreen == 1){
            setBarBgColor(Color.lime);
        }
    }  
    
    vLastRet = vASum;
    
    return (vASum);   
}