Migrating to the new matplotlib codebase

========================================

Michael Droettboom has spent the last several month working on the

"transforms branch" of matplotlib, in which he rewrote from the ground

up the transformation infrastructure in matplotlib, whih many found

unintuitive and hard to extend. In addition to a cleaner code base,

the refactoring allows you to define your own trasformations and

projections (eg map projections) within matplotlib. He has merged his

work into the HEAD of the svn trunk, and this will be the basis for

future matplotlib releases.

If you are a svn user, we encourage you to continue using the trunk as

before, but with the understanding that you are now truly on the

bleeding edge. Michael has made sure all the examples still pass with

the new code base, so for the vast majority of you, I except to see

few problems. But we need to get as many people as possible using the

new code base so we can find and fix the remaining problems. We have

take the svn cde used in the last stable release in the 0.91 series,

and made it a maintenance branch so we can still fix bugs and support

people who are not ready to migrate to the new transformation

infrastructure but nonetheless need acccess to svn bug fixes.

The experimental transforms refactoring changes have been merged into

SVN trunk. While this version is passing all examples and unit tests,

there may be changes that subtly break things that used to work, raise

nasty exceptions or kill innocent puppies. To help move matplotlib

forward, we encourage all users who are comfortable with the bleeding

edge to use the trunk with their own plots and report any bugs to the

mailing list.

Using the new code

==================

To check out the trunk with the latest transforms refactoring:

> svn co https://matplotlib.svn.sourceforge.net/svnroot/matplotlib/trunk/matplotlib

If you already have a working copy of the trunk, your next "svn up" will

include the latest transforms refactoring.

Using the old svn code

======================

To check out the maintenance branch, in order to commit bugfixes to 0.91.x:

> svn co https://matplotlib.svn.sourceforge.net/svnroot/matplotlib/branches/v0_91_maint matplotlib_0_91_maint

Any applicable bugfixes on the 0.91.x should be merged into the trunk so

they are fixed there as well.

API CHANGES in the new transformation infrastructure

====================================================

While Michael worked hard to keep the API mostly unchanged while

performing what has been called "open heart surgery on matplotlib",

there have been some changes, as discussed below.

The primary goal of this refactoring was to make it easier to

extend matplotlib to support new kinds of projections. This is

primarily an internal improvement, and the possible user-visible

changes it allows are yet to come.

These changes are detailed in the API_CHANGES document