DPO for Amibroker (AFL)

// By  : Bill Halliday
// Date: 2006-12-05
// From: A customized version of the 'DPO - Detrended Price 
//       Oscillator' Indicator found in:
//       Program Files/AmiBroker/Formulas/Indicators that 
//       displays a shaded plot using styleCloud
//
// Initial Alterations:
//
//       1) This documentation.
//       2) Printf statement.
//       3) Changed the Plot to include shading.
//
// Revision: 2006-12-07
//
//        Moved the Interpretation commentary to a "Status" 
//        'if block' AND added line feeds to the Interpretation 
//        printf for display clarity.


// Define the DPO function

function DetrendedPriceOsc( Periods ) 
{ 
return C - Ref( MA( C, Periods ), -( 1 + Periods/2 ) ); 
} 

// Start of program execution

// Call the dpo function

dpo = DetrendedPriceOsc( Param("Periods", 20, 1, 100 ) ); 

//Plot the DPO Indicator

PlotOHLC( dpo, dpo, 0,dpo ,  _DEFAULT_NAME(), colorLime, styleCloud ); 

// Start Revision: 2006-12-07
if( Status("action") == actionCommentary ) 
{ 
// this printf prints information into the Interpretation Window
printf ( Interval(2) + " " + Name()+"("+FullName()+"):\n\n" + 
         "High " + H + ",\nLow " + L + ",\nClose " + C + ", \n\n" +
         "dpo: " + DetrendedPriceOsc( Param("Periods", 20, 1, 100 ) ));
}
// End Revision: 2006-12-07