What's new in matplotlib 0.54
=============================
I've done a lot of rewriting of the core of matplotlib to support some
new features - mainly fast handling of polygon collections (pcolor and
scatter) and since the changes were pervasive, I took to opportunity
to fix some things that were bugging me about the design of
matplotlib. If you use the API, creating your own Axes, Subplots,
Lines, Rectangles, Texts, or working directly with transforms and
bboxes, you will need to upgrade your code, since the constructors of
all these objects have been simplified. The major changes affecting
users of the matlab interface are for pcolor and scatter. These
changes and others are detailed below and in
http://matplotlib.sf.net/API_CHANGES. Sorry for the pain - in the
long run, the new design is much cleaner and easier to work with, and
as far as I can see, will be stable.
More general transformation architecture
----------------------------------------
Earlier versions of matplotlib handled transformation of x and y
separately (ie we assumed all transformations were separable) but this
makes is difficult to do rotations or polar transformations, for
example. The new transformation lays the framework for doing general
transformations; see the transforms module
http://matplotlib.sf.net/matplotlib.transforms.html.
More efficient pcolor
---------------------
pcolor is now implemented with matplotlib.collections. polygon
collections which should provide significantly faster performance
across backends. The return value from pcolor is now a PolyColleciton
object rather than a list of patches, but the API is largely
compatible. See http://matplotlib.sf.net/API_CHANGES. The old function
pcolor_classic is retained for full backward compatibility.
New scatter plots
-----------------
The http://matplotlib.sf.net/matplotlib.matlab.html#-scatter command
is rewritten, and is implemented in the backend with a new polygon
collection class. For large scatter plots, the performance is 5 times
faster across all backends and 10 times faster for the *Agg
backends. Also, scatter works with many symbols: diamonds, sqaures,
oriented triangles, circles and more. As with pcolor, the scatter
command returns a collection instance rather than a list of patches as
before; see See http://matplotlib.sf.net/API_CHANGES
Also the size argument is now in points^2 (the area of the symbol in
points) and is not in data coords as before. This fixes a few
problems: symbols are not skewed by unequally shaped axes, scatter
works with log coords w/o distoring the symbol, and it is matlab
compatible.
The function scatter_classic is the old scatter function and will work
identically.
Enhanced mathtext
-----------------
A significant rewrite of the mathtext module provides much more
precise layout. The freetype component has been factored out of the
layout engine and replaced by an abstract class for font
handling. This lays the groundwork for ps mathtext. The text clipping
problems have been fixed. Added spacing commands '\/' (small space)
and '\ ' (regular space), and '\hspace{frac}' (space is fraction of
pointsize) as well as composite chars such as \angstrom. Fixed
over/under subscripts so you can say x_i^j and nested subscripts if
you do x_i_{j} (you need the curlys)
Many new plot symbols and markers
---------------------------------
Thanks Gary Ruben. See
http://matplotlib.sf.net/matplotlib.matlab.html#-plot
Font cacheing
-------------
Paul Barrett added caching support to the font manager to increase
performance. This and other changes have dramatically improved
postscript backend performance.
Newlines in text
----------------
After much encouragement from Al, I finally got around to supporting
newline separated text in the Text frontend, so this is no longer
backend dependent. As a bonus, it even works with arbitrary
rotations. There is an additional text attribute 'multialignment' that
specifies the alignment of the lines in multiline text. See
http://matplotlib.sf.net/examples/multiline.py and
http://matplotlib.sf.net/screenshots.html#align_text. Works with all
text instances except mathtext.
Axes hold
---------
matlab compatible hold command determines whether subsequent plot
commands overlay current plot or clear the axes by default. Default
setting is set in matplotlibrc and toggled by the hold command.
New rc file options
-------------------
You can control grid properties and tick padding (the space between
the axes and tick label) in matplotlibrc. The new options and defaults
are
axes.hold : True # whether to clear the axes by default on
# each plot command. Toggle with hold command
grid.color : k # grid color
grid.linestyle : : # dotted
grid.linewidth : 0.5 # in points
tick.major.pad : 4 # distance to major tick label in points
tick.minor.pad : 4 # distance to the minor tick label in points
Full dash control
-----------------
You can precisely control the dashes with a sequence of on off ink in
points. See http://matplotlib.sf.net/examples/dash_control.py
Removed close buttons from GUI
------------------------------
Steve Chaplin persuasively argued these were a bad idea. It's taken me
a while not to instinctively try and click on the missing buttons, but
I'm used to it now.
Properly aligned text with arbitrary alignments
-----------------------------------------------
You can now expect horizontal and vertical alignment specifications to
work with text at an arbitrary angle, eg, 45 degrees. See
http://matplotlib.sf.net/examples/alignment_test.py
Added stem plotting command
---------------------------
See http://matplotlib.sf.net/matplotlib.matlab.html#-stem and
http://matplotlib.sf.net/examples/stem_plot.py
Bug fix roundup
---------------
Executive summary: fixed ps centering, errorbar autoscaling, constant
data plot, copy tick attribute, mathtext fontsizing in interactive
mode, missing draw if interactive, some numerix/numarray
incompatibilities in type handling, agg memory leak, wx tooltips and
close not returning interpreter.
See http://matplotlib.sf.net/CHANGELOG for details.
Downloads at http://sourceforge.net/projects/matplotlib
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