[python-control-announce] Version 0.4b of python-control released

[Richard M. <mu...@cd...>]

Version 0.4b of the Python Control Systems Library (python-control) has just been posted to SourceForge.  The main changes for this version are:

* Initial implementation of model reduction functions: hsvd(), modred(), balred(), courtesy of Brandt Belson, Steve Brunton, Kevin Chen, and Lauren Padilla. 

* Changes to (eventually) support MIMO transfer functions.  These should be transparent to users of the MATLAB interface (control.matlab), but control functions now use a separate class structure.  Courtesy randt Belson, Steve Brunton, Kevin Chen, and Lauren Padilla.

* Updated functionality for Nichols charts, courtesy Allan McInnes.

* Improvements in unwrap function, courtesy Sawyer Fuller.

You can download this version of the code from SourceForge

  https://sourceforge.net/projects/python-control/files

There examples subdirectory has also been updated to contain the code for the PVTOL LQR and nested controller design (see project wiki page).  If you would like all of the test files and additional examples, you can check out the source distribution using subversion:

  svn co https://python-control.svn.sourceforge.net/svnroot/python-control/tags/control-0.4b control-0.4b

A more detailed list of changes is included below (starting from 0.4a, which was the Princeton branch of the code).

-richard

2011-04-02  Richard Murray  <mu...@ma...>

	* src/__init__.py: removed import of tests module (moved to tests/)

	* src/matlab.py: Added hsvd, balred, modred to list of functions
	that are imported for use as is.  Updated documentation string to
	indicate that these are implemented, along with a few other
	functions (zero, lqr) that weren't properly listed.

	* src/modelsimp.py (balred): Removed extraneous print statements
	(modred): Set method to be 'matchdc' by default (to match MATLAB)

	* src/__init__.py: added missing import of modelsimp functions

	* tests/slycot_convert_test.py (TestSlycot.testTF): turned off print
	statements in unit test to make it easier to see results.  Use
	verbose=True to turn back on.

	* tests/convert_test.py (TestConvert.testConvert): got rid of print
	statements in unittest; clutters the output so that you can't see
	the errors clearly.  Use verbose=True to turn back on.

	* src/statesp.py (_convertToStateSpace): removed "buggy" print
	statements 

	* src/xferfcn.py (_convertToTransferFunction): removed "buggy" print
	statements 

	* tests/nichols_test.py (TestStateSpace.testNgrid): updated testcode
	to turn off grid in initial Nichols chart plot.

	* src/freqplot.py: updated comments at top of file to reflect
	nichols chart move

	* src/nichols.py: transferred over changes from v0.3d

	* src/matlab.py (ngrid): moved import to function

2011-03-31  Richard Murray  <mu...@ma...>

	* examples/pvtol-nested.py: updated stability margin plot to use
	proper calling format for bode().

	* src/statesp.py (_convertToStateSpace): moved slycot import
	to the location where it is actually needed (allows running some
	commands without slycot installed)

	* src/xferfcn.py (_convertToTransferFunction): moved slycot import
	to the location where it is actually needed (allows running some
	commands without slycot installed)

	* src/nichols.py: new file for Nichols plot routines; move
	nichols(), nichols_grid(), closed_loop_contours(), m_circles(),
	n_circles()

	* src/__init__.py, src/freqresp.py, src/matlab.py: updated to match
	new file structure for Nichols charts

	* src/nichols.py (nichols): updated processing of freqresp to take
	into account the fact that return arguments are now a matrix of
	results (even for a SISO system)

2011-03-30  Richard Murray  <mu...@ma...>

	* tests/: added top level subdirectory, to be used for unit tests.
	The idea in putting the code here is that you can do 'setup.py test'
	during installation to make sure everything is working correctly.
	The test code would normally *not* be callable from the installed
	module. 

	* tests/*_test.py: moved from src/Test*.py

	* setup.py: updated version number.

2011-02-13  Richard Murray  <mu...@su...>

	* src/*.py: added svn:keywords Id properly

	* src/matlab.py (ngrid): added ngrid() from v0.3d

	* src/freqplot.py (nichols_grid, closed_loop_contours, m_circles,
	n_circles): copied over changes from Allan McInnes in v0.3d; ngrid()
	functiality + split out some of the nichols chart code into separate
	functions