// COG timing indicator
// AFL translation by E.M.Pottasch, 2011
// from: http://chartstudio.whselfinvest.com/files/COGTiming.ctl

bi=BarIndex();	
eb=LastValue(bi);	
period=Param("Period",5,1,10,1);	
bars=Param("Lookback Period",100,50,500,1);
sv=ParamToggle("Use Selected Value","Off|On",1);
level1=4;
level2=8;
ul1=ul2=ll1=ll2=Null;
oo=hh=ll=cc=Null;
 
if (sv)
{
	eb=SelectedValue(bi);
	bb=Max(0,eb-bars);
}
else
{
	bb=Max(0,eb-bars);
}
for(i=bb+period-1;i<=eb;i++)
{
	ul1[i]=level1;
	ul2[i]=level2;
	ll1[i]=-level1;
	ll2[i]=-level2;
	am=0;
	ar=0;
	for(j=i-period+1;j<=i;j++)
	{
		am=am+(High[j]+Low[j])/2;
		ar=ar+(High[j]-Low[j])/5;
	}
	am=am/period;
	ar=ar/period;
	if(ar!=0)
	{
		oo[i]=(Open[i]-am)/ar;
		hh[i]=(High[i]-am)/ar;
		ll[i]=(Low[i]-am)/ar;
		cc[i]=(Close[i]-am)/ar;
	}
	else
	{
		oo[i]=0;
		hh[i]=0;
		ll[i]=0;
		cc[i]=0;
	}
}
C=cc;O=oo;H=hh;L=ll;
Plot(C,"",colorWhite,styleCandle);
//PlotOHLC(O,H,L,C,"",colorWhite,styleCandle);
//Plot(cc,"Close",colorWhite,styleThick);
//Plot(oo,"\nOpen",colorLightGrey,styleLine);
//Plot(hh,"\nHigh",colorRed,styleLine);
//Plot(ll,"\nLow",colorRed,styleLine);
Plot(ul1,"\nUpper Level 1",colorViolet,styleLine);
Plot(ul2,"\nUpper Level 2",colorViolet,styleLine);
Plot(ll1,"\nLower Level 1",colorViolet,styleLine);
Plot(ll2,"\nLower Level 2",colorViolet,styleLine);