balred() now has 'matchdc' option and may handle unstable systems and will accept a list of 'orders'. gram() now does Cholesky factored gramians if desired. Requires slycot routines AB09MD, AB09ND, SB03OD.

mdclemen · mdclemen · commit f74e66552aa3 · 2017-01-03T09:18:01.000-08:00
diff --git a/control/modelsimp.py b/control/modelsimp.py
@@ -50,7 +50,7 @@
 from .statesp import StateSpace
 from .statefbk import gram
 
-__all__ = ['hsvd', 'balred', 'modred', 'era', 'markov', 'minreal',]
+__all__ = ['hsvd', 'balred', 'modred', 'era', 'markov', 'minreal']
 
 # Hankel Singular Value Decomposition
 #   The following returns the Hankel singular values, which are singular values
diff --git a/control/statefbk.py b/control/statefbk.py
@@ -347,8 +347,7 @@ def gram(sys,type):
     #Check for ss system object
     if not isinstance(sys,statesp.StateSpace):
         raise ValueError("System must be StateSpace!")
-    gramtypes = ['c', 'o', 'cf', 'of']
-    if type not in gramtypes:
+    if type not in ['c', 'o', 'cf', 'of']:
         raise ValueError("That type is not supported!")
 
     #TODO: Check for continous or discrete, only continuous supported right now
