RE: [Matplotlib-users] wxList and FigureCanvasWx

[Engelsma, D. <D.E...@La...>]

Hello --

I'm having a dickens of a time getting this to work...

I believe I understand what you mean about maintaining a list of
FigureCanvasAggs and using string & bitmap methods to get the figures into
my wxDialog.

Where I'm stuck is in plotting a histogram to a FigureCanvasAgg... I've
checked out your examples, but there doesn't appear to be anything that
directly uses FigureCanvasAgg. I've tried many different ways (mostly based
on the embedded_in_wx.py and histogram_demo.py examples).

Based on the example "histogram_demo.py" could you please give some pointers
as to how to plot the histogram to a FigureCanvasAgg? I think I can handle
things after that...

Thanks for your assistance!

Dave Engelsma
Lacks Wheel Trim Systems


> -----Original Message-----
> From: John Hunter [mailto:jdh...@ac...]
> Sent: Saturday, April 24, 2004 9:53 AM
> To: Engelsma, Dave
> Cc: mat...@li...
> Subject: Re: [Matplotlib-users] wxList and FigureCanvasWx
> 
> >>>>> "Engelsma," == Engelsma, Dave <D.E...@La...> writes:
> 
>     Dave> Hello - I''ve got a wxDialog where, among other
>     Dave> controls, I have a wxList and a
>     Dave> FigureCanvasWx. Depending on what single item is
>     Dave> selected in the wxList, the FigureCanvasWx should show
>     Dave> the appropriate graph. It's important that the
>     Dave> matplotlib-generated graph stay in the dialog along
>     Dave> with the other controls (I don't want to generate a
>     Dave> separate frame for the graph).
> 
> I'm not a wx guru, so this may not be the best way, but it I think it
> is a pretty good way.  Instead of putting a FigureCanvasWX in your,
> use a wxPanel instead.  Maintain a list of FigureCanvasAgg and use
> them to draw your figures.  Transfer these to the wxPanel using string
> and bitmap methods.  This is effectively what wxagg does.  The main
> difference is that you will have one canvas and a list of
> FigureCanvasAggs.
> 
> You can get the width and height of the figure you need to draw with
> 
> 
> 
> Suppose agg below is an FigureCanvasAgg instance
> 
>         agg.draw()
>         s = agg.tostring_rgb()
>         l,b,w,h = agg.figure.get_window_extent().get_bounds()
>         image = wxEmptyImage( w,h )
>         image.SetData(s)
>         bitmap = image.ConvertToBitmap()
> 
> You can then transfer the bitmap to the wxpanel.  If you want to do
> all the 'draw' calls upfront so you don't have to repeatedly draw if
> the user selects one figure, then another, then the original, that
> will be fine.
> 
> Agg is a pretty fast renderer, which may more than make up for the
> performance hit of having to go through the string->bitmap->canvas.
> 
> Let me know how it goes.
> 
> JDH