[amibroker] how to convert from bar value to pixel if the chart is in log schale

["zdomokos" <zdomokos@xxxxxxxxx>]

If the underlying chart is in log scale, then the chart and the calculated Y values do not match. Does anybody know how to convert from bar value to pixel if the chart is in log schale? 
Thanks.


http://www.amibroker.com/kb/2009/03/30/how-to-convert-from-bar-value-to-pixel-co-ordinates/


--- In amibroker@xxxxxxxxxxxxxxx, "Ara Kaloustian" <ara1@xxx> wrote:
>
> //functions for Converting Chart prices to pixels
> 
> function GfxConvertBarToPixelX( bar )
> 
> {
> 
> lvb = Status( "lastvisiblebar" );
> 
> fvb = Status( "firstvisiblebar" );
> 
> pxchartleft = Status( "pxchartleft" );
> 
> pxchartwidth = Status( "pxchartwidth" );
> 
> //
> 
> if ( diag )
> 
> {
> 
> //_TRACE("FP&T-xx " + " lvb " + WriteVal(Lvb,1.0) + " fvb " + 
> WriteVal(fvb,1.0) + "pxw " + WriteVal(pxchartwidth,1.0)
> 
> // + "pxleft " + WriteVal(pxchartleft,1.0));
> 
> }
> 
> return pxchartleft + ( bar - fvb ) * pxchartwidth / ( Lvb - fvb + 1 );
> 
> }
> 
> function GfxConvertValueToPixelY( Value )
> 
> {
> 
> local Miny, Maxy, pxchartbottom, pxchartheight;
> 
> Miny = Status( "axisminy" );
> 
> Maxy = Status( "axismaxy" );
> 
> pxchartbottom = Status( "pxchartbottom" );
> 
> pxchartheight = Status( "pxchartheight" );
> 
> return pxchartbottom - floor( 0.5 + ( Value - Miny ) * pxchartheight / ( 
> Maxy - Miny ) );
> 
> }
> 
> ----- Original Message ----- 
> From: "wooziwog" <xcitemint@xxx>
> To: <amibroker@xxxxxxxxxxxxxxx>
> Sent: Thursday, July 09, 2009 8:12 PM
> Subject: [amibroker] GFX x y position conversion question
> 
> 
> > Does anyone know if there is a way to convert the X and Y coordinates from 
> > the price chart directly to X and Y pixel coordinates?
> > I simply want to draw polygon shapes of chart patterns.  Since I already 
> > have the pivots and lines on my current chart I simply want to  do a color 
> > fill.  I don't want to have to do loops to recreate everything that I 
> > already have.
> >
> > Any help is appreciated.
> >
> > I will post the completed project if I can find a way of doing this.
> >
> > David K.
> >
> >
> >
> > ------------------------------------
> >
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> >
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> >
> >
>




------------------------------------

**** IMPORTANT PLEASE READ ****
This group is for the discussion between users only.
This is *NOT* technical support channel.

TO GET TECHNICAL SUPPORT send an e-mail directly to 
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TO SUBMIT SUGGESTIONS please use FEEDBACK CENTER at
http://www.amibroker.com/feedback/
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