Chaloke Peak and Trough for Amibroker (AFL)

///// Chaloke.com Peak-Trough System 1.0 ///// 

X=1; 
Constant= 0.000; 

UpperO= Ref(Peak(C,X),-1); 
LowerO= Ref(Trough(C,X),-1); 
Upper= UpperO*(1 + Constant ); 
Lower= LowerO*(1 - Constant ); 

Buy = Cross(C, Upper); 
Sell= Cross(Lower,C); 

Color=IIf(BarsSince(Buy)<BarsSince(Sell),ParamColor("Bullish",colorBrightGreen),ParamColor("Bearish",colorRed));
Plot(C,"CDC Peak & Trought V.1.005",Color,64); 
Plot(Zig(C,X),"",ParamColor("Zigzag",colorWhite),styleDashed); 
Plot(Upper,"",ParamColor("Upper",colorBlue),styleDashed); 
Plot(Lower,"",ParamColor("Lower",colorOrange),styleDashed); 
PlotShapes(shapeUpArrow*Buy,ParamColor("UpArrow",10),0,L); 
PlotShapes(shapeDownArrow*Sell,ParamColor("DownArrow",11),0,H);

_SECTION_BEGIN("EMA");
P = ParamField("Price field",-1);
Periods = Param("Periods", 15, 2, 200, 1, 10 );
Plot( EMA( P, Periods ), _DEFAULT_NAME(), ParamColor( "Color", colorCycle ), ParamStyle("Style") );