Amibroker AFL code for double tops and bottoms:
Script:
_SECTION_BEGIN(“Detecting double tops and bottoms”);
/* Detecting double tops and bottoms*/
percdiff = 5; /* peak detection threshold */
fwdcheck = 5; /* forward validity check */
mindistance = 10;
validdiff = percdiff/400;
PK= Peak( H, percdiff, 1 ) == High;
TR= Trough( L, percdiff, 1 ) == Low;
x = Cum( 1 );
XPK1 = ValueWhen( PK, x, 1 );
XPK2 = ValueWhen( PK, x, 2 );
xTR1 = ValueWhen( Tr, x, 1 );
xTr2 = ValueWhen( Tr, x, 2 );
peakdiff = ValueWhen( PK, H, 1 )/ValueWhen( PK, H, 2 );
Troughdiff=ValueWhen( tr, L, 1 )/ValueWhen( tr, L, 2 );
doubletop = PK AND abs( peakdiff – 1 ) < validdiff AND (Xpk1 -Xpk2)>mindistance AND High > HHV( Ref( H, fwdcheck ), fwdcheck – 1 );
doubleBot=tr AND abs( troughdiff – 1 ) < validdiff AND (Xtr1 -Xtr2)>mindistance AND Low < LLV( Ref( L, fwdcheck ), fwdcheck – 1 );
Buy = doublebot;
Sell = doubletop;
for( i = 0; i < BarCount; i++ )
{
if( Buy[i] ) PlotText( “BOT ” , i, L[ i ],colorYellow );
if( Sell[i] ) PlotText( “TOP” , i, H[ i ], colorWhite );
}
WriteIf( Highest( doubletop ) == 1, “AmiBroker has detected some possible
double top patterns for ” + Name() + “\nLook for green arrows on the price
chart.”, “There are no double top patterns for ” + Name() );
WriteIf(Lowest( doublebot)==1,”AmiBroker has detected some possible double
bottom patterns for ” + Name() + “\nLook for red arrows on the price
chart.”, “There are no double bottom patterns for ” + Name() );
_SECTION_END();
_SECTION_BEGIN(“Price”);
SetChartOptions(0,chartShowArrows|chartShowDates);
_N(Title = StrFormat(“{{NAME}} – {{INTERVAL}} {{DATE}} Open %g, Hi %g, Lo %g, Close %g (%.1f%%) {{VALUES}}”, O, H, L, C, SelectedValue( ROC( C, 1 ) ) ));
Plot( C, “Close”, ParamColor(“Color”, colorDefault ), styleNoTitle | ParamStyle(“Style”) | GetPriceStyle() );
_SECTION_END();