help with P&f chart

_SECTION_BEGIN("Point&Figure");

//--Modified by KelvinHand--------
// Changes:
// * Optimize the code, remove unused statements inside the looping.
// * Improve readability


GraphXSpace = 5;
SetChartBkColor( ParamColor( "BackGroundColor", colorBlack) );

X_Color = ParamColor( "X_Color", colorBrightGreen );
O_Color = ParamColor( "O_Color", colorRed);


PlotGridLines = ParamToggle( "PlotdGrid", "No|Yes", 1 ) ;
GridColor = ParamColor( "GridColor", colorGrey50 );
TextColor = ParamColor( "TextColor", colorBlue );  //--KH: Add Selectable Text Color instead of blue

Scaling = ParamList( "Scaling Method", "Traditional|Percentage|AVG True Range",2);
ATRPer = Param("ATR Period", 20, 1); //--KH: Add Changeable Period for ATR

//--KH: Previous Code, use 3 Param() of difference cases. 
// so the improvement as follow:
Box = Param( "Box", 1, 0.2, 10, 0.1 );

	if ( scaling == "Percentage" )
		Box = (Box /100) * LastValue( C );
	else
	if ( scaling == "AVG True Range" )
	{
             // - org. Box = Param( "Box", 1, 0.2, 5, 0.1 );
	    if (Box>5) Box=5; 
		Box = Box * LastValue( ATR ( ATRPer ));
	}

Reverse = Param( "Reverse", 3, 1, 5 );


shiftChart = 0;
shiftLastClose = 1;
shiftGrid = 7;
shiftPriceAxis = 2;



j = 0;
PFL[j] = Box * ceil( Low[j] / Box ) + Box;
PFH[j] = Box * floor( High[j] / Box );

direction[j] = 0;

	for ( i = 1; i < BarCount; i++ )
	{
		if ( direction[j] == 0 )
		{
			if ( Low[i] <= PFL[j] - Box )
				PFL[j] = Box * ceil( Low[i] / Box );
			else
			{
				if ( High[i] >= PFL[j] + Reverse*Box )
				{
					j++;
					direction[j] = 1;
					PFH[j] = Box * floor( High[i] / Box );
					PFL[j] = PFL[j - 1] + Box;
				}
			}
		}
		else
		{
			if ( High[i] >= PFH[j] + Box )
				PFH[j] = Box * floor( High[i] / Box );
			else
			{
				if ( Low[i] <= PFH[j] - Reverse * Box )
				{
					j++;
					direction[j] = 0;
					PFH[j] = PFH[j - 1] - Box;
					PFL[j] = Box * ceil( Low[i] / Box );
				}
			}
		}

	}

	delta = BarCount - j - 1;
	direction = Ref( direction, - delta );

	Hi = Ref( PFH, -delta ) + Box / 2;
	Lo = Ref( PFL, -delta ) - Box / 2;
	Cl = IIf( direction == 1, Hi, Lo );
	Op = IIf( direction == 1, Cl - Box, Cl + Box );

	Graphcolor = IIf( direction == 1, X_Color, O_Color);
	PlotOHLC( Op, Hi, Lo, Cl, "", GraphColor,  stylePointAndFigure|styleNoLabel, 0, 0 , shiftChart );
	

	Last = Ref( LastValue( C ), -( BarCount - 1 ) );
	Plot( Last, "", colorRed, styleNoLine | styleDots, 0 , 0, shiftLastClose );


	//-----------------------------------------------------------------------
	// GRID CONSTRUCTION
	//----------------------------------------------------------------------
	if ( PlotGridLines )
	{
		begin = SelectedValue( BarIndex() );
		end = LastValue( BarIndex() );
		period = end - begin + 1;

		if ( begin < end )
		{
			ScreenHigh = LastValue( HHV( cl, period ) );
			ScreenLow = LastValue( LLV( Cl, period ) );
			top = LineArray( begin - shiftGrid, screenHigh, end, screenhigh, 0 , 1 );
			Bot = LineArray( begin - shiftGrid, screenlow, end, screenLow, 0, 1 );

			Plot( top, "", gridColor, styleLine | styleNoLabel , 0, 0, shiftGrid );
			//Plot( bot, "", gridColor,styleLine|styleNoLabel, 0 , 0 , shiftGrid);

			VerticalGrid = IIf ( BarIndex() >= begin, IIf( direction == 1, screenHigh, screenLow ), Null );
			Plot ( VerticalGrid, "", gridColor, styleStaircase | styleNoLabel, 0, 0, 1 );

			for ( n = LastValue( bot ); n < LastValue( top ) - 0.5*box; n+=box,  bot += box)
			{
				Plot( bot , "", gridColor, styleLine | styleNoLabel, 0, 0 , shiftGrid );
				
				text = NumToStr( LastValue( bot ) + 0.5 * box, 8.2 );
				xposition = BarCount + shiftPriceaxis;
				yPosition = LastValue( bot ) + 0.27 * box;
				PlotText( text, xPosition , yPosition, TextColor );
			}
		}
	}



//---------------------------------------------------------------------
// TITLE
//----------------------------------------------------------------------
Title = "\n Instrument : " + Name() + " - "+ FullName() + 
		"\n Formula : " + " Point & Figure (High/Low Range)" +
		"\n Box : " + NumToStr( Box, 4.4 ) + " " + "Reverse : " + NumToStr( Reverse, 2.0 ) + 
		"\n ATR : " + WriteVal( LastValue( ATR( 100 ) ), format = 4.4 );

_SECTION_END();