fixup! Move ss, tf2ss, etc into statesp module

cwrowley · cwrowley · commit 5cf3e021a701 · 2015-04-26T19:16:06.000-04:00
diff --git a/control/matlab/__init__.py b/control/matlab/__init__.py
@@ -1204,26 +1204,6 @@ def lsim(sys, U=0., T=None, X0=0.):
     T, yout, xout = timeresp.forced_response(sys, T, U, X0, transpose = True)
     return yout, T, xout
 
-# Return state space data as a tuple
-def ssdata(sys):
-    '''
-    Return state space data objects for a system
-
-    Parameters
-    ----------
-    sys: LTI (StateSpace, or TransferFunction)
-        LTI system whose data will be returned
-
-    Returns
-    -------
-    (A, B, C, D): list of matrices
-        State space data for the system
-    '''
-    from ..statesp import _convertToStateSpace
-    ss = _convertToStateSpace(sys)
-    return (ss.A, ss.B, ss.C, ss.D)
-
-# Return transfer function data as a tuple
 def tfdata(sys):
     '''
     Return transfer function data objects for a system
diff --git a/control/statesp.py b/control/statesp.py
@@ -63,7 +63,7 @@
 from .xferfcn import _convertToTransferFunction
 from copy import deepcopy
 
-__all__ = ['StateSpace', 'ss', 'rss', 'drss', 'tf2ss']
+__all__ = ['StateSpace', 'ss', 'rss', 'drss', 'tf2ss', 'ssdata']
 
 class StateSpace(LTI):
     """A class for representing state-space models
@@ -1133,3 +1133,20 @@ def drss(states=1, outputs=1, inputs=1):
     """
 
     return _rss_generate(states, inputs, outputs, 'd')
+
+def ssdata(sys):
+    '''
+    Return state space data objects for a system
+
+    Parameters
+    ----------
+    sys: LTI (StateSpace, or TransferFunction)
+        LTI system whose data will be returned
+
+    Returns
+    -------
+    (A, B, C, D): list of matrices
+        State space data for the system
+    '''
+    ss = _convertToStateSpace(sys)
+    return (ss.A, ss.B, ss.C, ss.D)
