Re: [Matplotlib-users] odd axis behavior

[Paul B. <ba...@st...>]

John Hunter wrote:

[snip, snip]
> 
> As I wrote then, I think the root of this bug is that matplotlib is
> doing the transforms in the front end and passing the backend display
> coordinates.  In some cases, you can get very odd display coordinates,
> eg very large positive or negative numbers, and I think this is what
> is causing agg to fail (I know agg has some canvas size limitations,
> something like 4096x4096 pixels if memory serves).  For some time I've
> been wanting to refactor the backend code to pass data + transform to
> the backend rather than transformed data.  This would fix a lot of
> little bugs, eg some subpixel artifacts in agg that I've had to hack
> around by special casing, and would improve performance on some
> backends, like PS and SVG where you can simply provide the data
> coordinates and the vec 6 affine and let the display device handle the
> transformations.

Yeah!

> It's a fairly big change, and requires some thought as to how to do it
> right in the presence of nonlinear/nonseparable transformations, but
> it's on the list.

Excellent!

[snip, snip]

  -- Paul

-- 
Paul Barrett, PhD      Space Telescope Science Institute
Phone: 410-338-4475    ESS/Science Software Branch
FAX:   410-338-4767    Baltimore, MD 21218