ZigZag with buy and sell signals for Amibroker (AFL)

_SECTION_BEGIN("zigzag3");
array = Close;
amount = Param("Amount", 15.5, 1, 50, 0.5 );
zz0 = Zig( array, amount );
zz1 = Ref( zz0, -1 );
zz2 = Ref( zz0, -2 );
tr = ValueWhen(zz0 > zz1 AND zz1 < zz2, zz1);
pk = ValueWhen(zz0 < zz1 AND zz1 > zz2, zz1);
PU = tr + 0.01 * abs(tr)*amount;
PD = pk - 0.01 * abs(pk)*amount;
ZZT = IIf( array >= PU AND zz0 > zz1, 1,
IIf( array <= PD AND zz0 < zz1, -1, 0 ) );
ZZT = ValueWhen( ZZT != 0, ZZT );
// plot price bar chart
Plot( Close, "Price", colorBlack, styleBar );
// plot Zigzag and zigzag trend
Plot( ZZT, "ZigZagTrend", colorRed, styleOwnScale );
Plot( zz0, "ZigZag line", colorBlue, styleThick );
// Plot the ribbon
ribboncol= IIf( ZZT > 0, colorGreen, colorRed );
Plot( 2, "ZZT Ribbon", ribboncol, styleArea | styleOwnScale | styleNoLabel, 0, 100 );
GraphXSpace = 10;
Buy = Cover = Cross( ZZT, 0 );
Sell = Short = Cross( 0, ZZT );
// plot arrows
PlotShapes( Buy + 2 * Sell, ribboncol, 0, IIf( Buy, L, H ), -30 );
_SECTION_END();