[SciPy-user] pyqwt or matplotlib

[John Hunter]

On Tue, Aug 26, 2008 at 3:54 PM, Bryan Cole <bryan at cole.uklinux.net> wrote:

> Another exception may also be for scatter plots with a symbol at each
> point. The newer drawing APIs place a lot of emphasis on glyph rendering
> performance (for text rendering). If the points are rendered using the
> glyph-caching facilities of cairo, for example, this may beat AGG. I
> haven't tested this yet, however. I havn't checked how mpl does symbol
> rendering, so I'm not sure if this changes the mpl-vs-qwt question.

if the markers are homogeneous (same size, same color), eg from a plot
command like

   plot(x, y, 'o')

matplotlib agg does use cached glyph rendering and is fast.  For
non-homogeneous markers, eg in a 'scatter' where the color and/or size
vary with each marker, matlpotlib does not use any cacheing and is
pretty slow.

JDH