Re: [Matplotlib-users] Matplotlib performance

[Matt M. <mat...@gm...>]

> I agree that exploration of large data sets is an important application,
> and that we need to speed it up.  A couple days ago I added   automatic
> subsetting (but not decimation--although this could be added easily) to
> image drawing, and that made a big difference for panning and zooming
> using imshow or pcolorfast with regular grids.

Cool.  

Low-pass filtering is more work to implement and takes away from the 
computational gains, but it's necessary to prevent aliasing a la the 
Nyquist-Shannon theorem.

> An easy, built-in interface makes sense for line/marker plotting as
> well, but it will take some thought to figure out exactly what that
> interface should be.  The line plotting case (including things like
> scatter) is more complicated than the image.  Probably optimizations
> should be specified via kwargs, not by default.

true

> Clipping should not be to points inside the xlim, but should include one
> more point on each side so that lines go to the edge of the box.

Good point.  As I understand npy.searchsorted(), it should then be

  ind0 = npy.searchsorted(self.xorig, xlim[0], side='left')
  ind1 = npy.searchsorted(self.xorig, xlim[1], side='right')

instead of 

  ind0, ind1 = npy.searchsorted(self.xorig, xlim)