/*
Coppock Trade Signal v1.1 (01/28/09)

The Coppock formula was introduced in Barron's in 1962, devised by a San Antonio, TX-based technician, economist and investment advisor named Edwin Sedgwick Coppock.
Since then, the Coppock oscillator has been adopted and adapted by technicians around the world.

The Coppock curve is a long-term price momentum indicator used primarily to recognize major bottoms in the stock market.
It is calculated as a 10-month weighted moving average of the sum of the 14-month rate of change and the 11-month rate of change for the index.

A buy signal is formed when there is an upturn in the curve after an extreme low in the curve.
A sell signal is formed when there is a higher peak in stock prices but a lower peak in the Coppock curve.
These are the basic signals, more signals and interpretations are seen at more advanced levels.

AFL Author: rcef88
goriamtrader[at]yahoo.com
EliteVest, Public Mutual Bhd
*/

_SECTION_BEGIN("Coppock Trade Signal v1.1");

//PARAMETERS:
ROC1Periods		=Param("ROC1 periods",14,2,200,1,0);
ROC2Periods		=Param("ROC2 periods",11,2,200,1,0);
WMAPeriods			=Param("WMA periods",10,2,200,1,0);
CoppockCurve		=ParamToggle("Use Coppock curve","No|Yes",0);
CoppockBar			=ParamToggle("Use Coppock bar","No|Yes",1);
ColBull			=ParamColor("Bull color",colorBlue);
ColBear			=ParamColor("Bear color",colorRed);
UseTradeSignal	=ParamToggle("Use trade signal","No|Yes",1);
CoppockFilter		=Param("Coppock filter",20,2,200,1,0);
ColBuy				=ParamColor("Buy color",colorBrightGreen);
ColSell			=ParamColor("Sell color",colorDarkRed);
ColBg				=ParamToggle("Show background color","No|Yes",1);

//MAIN:
Coppock=WMA((ROC(C,ROC1Periods)+ROC(C,ROC2Periods)),WMAPeriods);
InitialCalculationLength=Max(ROC1Periods,ROC2Periods)+WMAPeriods;
for(i=0;i<BarCount;i++)
{
	if(i<InitialCalculationLength) //initial zero
	{
		Coppock[i]=0.0;
		if(UseTradeSignal){Buy=0; Sell=0;}
	}
}
LastCoppock1=Ref(Coppock,-1);
LastCoppock2=Ref(Coppock,-2);
TradeStatus=IIf(Coppock>0,IIf(Coppock>LastCoppock1,ColBull,IIf(Coppock<LastCoppock1,ColBear,IIf(Coppock==LastCoppock1 && LastCoppock1>LastCoppock2,ColBull,ColBear))),
			  IIf(Coppock>LastCoppock1,ColBull,IIf(Coppock<LastCoppock1,ColBear,IIf(Coppock==LastCoppock1 && LastCoppock1>LastCoppock2,ColBull,ColBear))));
StyleTitle=IIf(CoppockCurve && CoppockBar,styleNoTitle,0);
StyleLabel=IIf(CoppockCurve && CoppockBar,styleNoLabel,0);
if(CoppockCurve) Plot(Coppock,"Coppock"+_PARAM_VALUES(),TradeStatus,styleLine|styleThick|StyleTitle|StyleLabel);
if(CoppockBar) Plot(Coppock,"Coppock"+_PARAM_VALUES(),TradeStatus,styleHistogram|styleThick);
if(UseTradeSignal)
{
	CoppockIsBuy=TradeStatus==ColBull;
	CoppockIsSell=TradeStatus==ColBear;
	CoppockBuyValue=ValueWhen(CoppockIsBuy,Coppock,1);
	CoppockSellValue=ValueWhen(CoppockIsSell,Coppock,1);
	Buy=!Ref(CoppockIsBuy,-1) && Coppock<0 && CoppockIsBuy && abs(CoppockBuyValue)>=CoppockFilter;
	Sell=!Ref(CoppockIsSell,-1) && Coppock>0 && CoppockIsSell && abs(CoppockSellValue)>=CoppockFilter;
	PlotShapes(IIf(Buy,shapeUpArrow,shapeNone),ColBuy,0,Coppock,0);
	PlotShapes(IIf(Sell,shapeDownArrow,shapeNone),ColSell,0,Coppock,0);
}
if(ColBg) SetChartBkGradientFill(ParamColor("BgTop",colorWhite),ParamColor("BgBottom",colorTeal));

_SECTION_END();