[python-control-announce] python-control 0.6d released

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

Version 0.6d of the Python Control Systems Library (python-control) has been posted to SourceForge.  This adds a few new functions and fixes some bugs.

* Fixed a bug in dime.py that caused errors when using method 'tustin' or 'zoh'.

* Improved stability margin calculations, including support for FRD systems.

* Minimal realization support for transfer functions and state space systems.

* New MATLAB-like functions: append, connect, mineral

* Increased python3 compatibility.

A more detailed list of changes is included below (starting from 0.6c).

-richard

2014-03-22  Richard Murray  <mu...@si...>

	* src/matlab.py (ss): allow five arguments to create a discrete time
	system.  From Roberto Bucher, 12 Jan 2014

2014-03-22  Richard Murray  <mu...@si...>

	* src/bdalg.py (feedback): allow FRD for feedback()

2014-03-22  Richard Murray  <mu...@si...>

	* tests/discrete_test.py (TestDiscrete.test_sample_system): added
	conversions using tustin and zoh to catch 'dt' bug #5

	* src/dtime.py (sample_system): Changed 'dt' to 'Ts' to fix bug #4

	* tests/frd_test.py (TestFRD.testbdalg): added unit tests for bdalg
	functions operating on FRD data

	* src/bdalg.py (series, parallel, negate, feedback): updated
	documentation to note that FRD ovjects work.
	(feedback): updated conversions to allow for FRD

2013-07-15  Richard Murray  <mu...@al...>

	* src/frdata.py, src/xferfcn.py: updated to use __truediv__ and
	__rtruediv__ for compatibility with python3

2013-07-14  Richard Murray  <mu...@al...>

	* src/dtime.py (sample_system): added check to make sure
	cont2discrete is available in scipy.signal
	(sample_system): added docstring

2013-06-24  Richard Murray  <mu...@al...>

	* tests/minreal_test.py (TestMinreal.testMinrealBrute),
	src/xferfcn.py (_convertToTransferFunction), src/statesp.py
	(StateSpace.__rmul__), src/margins.py (stability_margins): changed
	exception syntax to be python3 compatibile (works for python2.6+)
	
2013-06-10  Richard Murray  <mu...@al...>

	* src/xferfcn.py (TransferFunction.horner): small fix to docstring

	* src/freqplot.py (nyquist_plot): small fix to docstring

2013-06-09  Richard Murray  <mu...@al...>

	* tests/bdalg_test.py (TestFeedback.testScalarSS)
	(TestFeedback.testScalarTF): added simple test of default argument
	to feedback() for state space and transfer function systems

	* tests/frd_test.py (TestFRD.testFeedback): added test of default
	argument to feedback() for FRD type

	* src/bdalg.py (feedback): 
	* src/frdata.py (FRD.feedback):
	* src/statesp.py (StateSpace.feedback):
	patched in default value of 1 for other system in feedback().
	Contributed by Ryan Krauss <rk...@si...>
	
	* tests/xferfcn_test.py (TestXferFcn.testEvalFrMIMO)
	(TestXferFcn.testEvalFrSISO): added tests of __call__ version of
	evalfr. 

	* src/xferfcn.py (TransferFunction.__call__): patched in new
	__call__ functionality from Ryan Krauss <rk...@si...>, but
	modified to use evalfr (works with MIMO).  SISO transfer functions
	return a single complex number, MIMO transfer functions return a
	matrix of complex numbers.

2013-05-23  Rene van Paassen <ren...@gm...>

	* src/margin.py: re-vamped stability_margins function. Now
          uses analytical method for TF and state-space, works on FRD
          objects too, and can optionally return all margins found for
          the analytical method.

	* src/xferfcn.py and src/frdata.py: Now return array result
          for fresp when called with an iterable frequency vector

	* src/xferfcn.py and src/statesp.py: added minreal functions

	* src/bdalg.py: implemented append and connect functions (old
          version, with indexes, not with names)
	  
	* src/matlab.py: added connect, append, minreal

	* src/xferfcn.py and src/statesp.py: added/corrected
          __rmul__. In most cases a gain matrix (np.matrix) may now be
          used in combination with ss or tf systems.

2012-11-10  Richard Murray  <mu...@al...>

	* src/canonical.py: new module implementing conversions to selected
	canonical forms: canonical_form(), reachable_form() implemented

	* src/lti.py (issiso): new function to quickly check if a system is
	single input, single output or not

2012-11-04  Richard Murray  <mu...@al...>

	* src/__init__.py: added action item to separate out matlab module
	functionality (eventually)

	* src/matlab.py: added code for setting up MATLAB defaults if matlab
	submodule is imported instead of main (control) module.  See
	comments in __init.py__ for what needs to be done to implement.

	* src/freqplot.py (bode_plot): moved default values of plotting
	options to config module to allow easier use override

	* src/config.py: new module to help set package defaults

	* src/xferfcn.py (_convertToTransferFunction): removed extraneous
	print statements if slycot is not installed

	* src/statesp.py (StateSpace.__str__): fixed error in printing
	timebase when dt is None (python 3)