Peak & Valley for Amibroker (AFL)

_SECTION_BEGIN("Peak & Valley");
// E.M.Pottasch 09/06/10
nbar = Param("nbar",2,1,5,1); 

PHigh = H > Ref(HHV(H,nbar),-1) AND Ref(HHV(H,nbar),nbar) < H;
PHighPrice0 = ValueWhen(PHigh,H);
PHighPrice1 = IIf(PHighPrice0 AND BarsSince(PHigh) > nbar,PHighPrice0,Null);
PHighPrice2 = IIf(PHighPrice0 AND BarsSince(PHigh) <= nbar,PHighPrice0,Null);
PLow = L < Ref(LLV(L,nbar),-1) AND Ref(LLV(L,nbar),nbar) > L;
PLowPrice0 = ValueWhen(PLow,L); 
PLowPrice1 = IIf(PLowPrice0 AND BarsSince(Plow) > nbar,PLowPrice0,Null);
PLowPrice2 = IIf(PLowPrice0 AND BarsSince(Plow) <= nbar,PLowPrice0,Null);

GraphXSpace = 5;
SetChartOptions(0, chartShowDates);
Plot(C,"\nLast",colorWhite,styleCandle);

Plot(PHighPrice1,"\nPHighPrice",colorOrange,styleThick);
Plot(PHighPrice2,"",colorOrange,styleDots | styleNoLine);
Plot(PLowPrice1,"\nPLowPrice",colorBrightGreen,styleThick);
Plot(PLowPrice2,"",colorBrightGreen,styleDots | styleNoLine);

Buy=H>PHighPrice0;
Sell=L<PLowPrice0;

Buy=ExRem(Buy,Sell);
Sell=ExRem(Sell,Buy);

PlotShapes(IIf(Buy , shapeSmallUpTriangle, shapeNone) ,colorGreen, 0,L,-30); 
PlotShapes(IIf( Sell, shapeSmallDownTriangle, shapeNone) ,colorOrange, 0,H,-25);
_SECTION_END();