ss, rss, drss return LinearIOSystem

murrayrm · murrayrm · commit f712096d4ddb · 2022-03-12T22:38:48.000-08:00
diff --git a/control/iosys.py b/control/iosys.py
@@ -32,6 +32,7 @@
 from warnings import warn
 
 from .statesp import StateSpace, tf2ss, _convert_to_statespace
+from .statesp import _ss, _rss_generate
 from .xferfcn import TransferFunction
 from .timeresp import _check_convert_array, _process_time_response, \
     TimeResponseData
@@ -40,8 +41,8 @@
 
 __all__ = ['InputOutputSystem', 'LinearIOSystem', 'NonlinearIOSystem',
            'InterconnectedSystem', 'LinearICSystem', 'input_output_response',
-           'find_eqpt', 'linearize', 'ss2io', 'tf2io', 'interconnect',
-           'summing_junction']
+           'find_eqpt', 'linearize', 'ss', 'rss', 'drss', 'ss2io', 'tf2io',
+           'interconnect', 'summing_junction']
 
 # Define module default parameter values
 _iosys_defaults = {
@@ -181,7 +182,8 @@ def __init__(self, inputs=None, outputs=None, states=None, params={},
     nstates = 0
 
     def __repr__(self):
-        return self.name if self.name is not None else str(type(self))
+        return str(type(self)) + ": " + self.name if self.name is not None \
+            else str(type(self))
 
     def __str__(self):
         """String representation of an input/output system"""
@@ -853,6 +855,10 @@ def _out(self, t, x, u):
             + self.D @ np.reshape(u, (-1, 1))
         return np.array(y).reshape((-1,))
 
+    def __str__(self):
+        return InputOutputSystem.__str__(self) + "\n\n" \
+            + StateSpace.__str__(self)
+
 
 class NonlinearIOSystem(InputOutputSystem):
     """Nonlinear I/O system.
@@ -2261,6 +2267,94 @@ def _find_size(sysval, vecval):
     raise ValueError("Can't determine size of system component.")
 
 
+# Define a state space object that is an I/O system
+def ss(*args, **kwargs):
+    return LinearIOSystem(_ss(*args, **kwargs))
+ss.__doc__ = _ss.__doc__
+
+
+def rss(states=1, outputs=1, inputs=1, strictly_proper=False):
+    """
+    Create a stable *continuous* random state space object.
+
+    Parameters
+    ----------
+    states : int
+        Number of state variables
+    outputs : int
+        Number of system outputs
+    inputs : int
+        Number of system inputs
+    strictly_proper : bool, optional
+        If set to 'True', returns a proper system (no direct term).
+
+    Returns
+    -------
+    sys : StateSpace
+        The randomly created linear system
+
+    Raises
+    ------
+    ValueError
+        if any input is not a positive integer
+
+    See Also
+    --------
+    drss
+
+    Notes
+    -----
+    If the number of states, inputs, or outputs is not specified, then the
+    missing numbers are assumed to be 1.  The poles of the returned system
+    will always have a negative real part.
+
+    """
+
+    return LinearIOSystem(_rss_generate(
+        states, inputs, outputs, 'c', strictly_proper=strictly_proper))
+
+
+def drss(states=1, outputs=1, inputs=1, strictly_proper=False):
+    """
+    Create a stable *discrete* random state space object.
+
+    Parameters
+    ----------
+    states : int
+        Number of state variables
+    inputs : integer
+        Number of system inputs
+    outputs : int
+        Number of system outputs
+    strictly_proper: bool, optional
+        If set to 'True', returns a proper system (no direct term).
+
+    Returns
+    -------
+    sys : StateSpace
+        The randomly created linear system
+
+    Raises
+    ------
+    ValueError
+        if any input is not a positive integer
+
+    See Also
+    --------
+    rss
+
+    Notes
+    -----
+    If the number of states, inputs, or outputs is not specified, then the
+    missing numbers are assumed to be 1.  The poles of the returned system
+    will always have a magnitude less than 1.
+
+    """
+
+    return LinearIOSystem(_rss_generate(
+        states, inputs, outputs, 'd', strictly_proper=strictly_proper))
+
+
 # Convert a state space system into an input/output system (wrapper)
 def ss2io(*args, **kwargs):
     return LinearIOSystem(*args, **kwargs)
diff --git a/control/matlab/__init__.py b/control/matlab/__init__.py
@@ -62,6 +62,7 @@
 
 # Control system library
 from ..statesp import *
+from ..iosys import ss, rss, drss       # moved from .statesp
 from ..xferfcn import *
 from ..lti import *
 from ..frdata import *
diff --git a/control/matlab/wrappers.py b/control/matlab/wrappers.py
@@ -3,7 +3,7 @@
 """
 
 import numpy as np
-from ..statesp import ss
+from ..iosys import ss
 from ..xferfcn import tf
 from ..ctrlutil import issys
 from ..exception import ControlArgument
diff --git a/control/sisotool.py b/control/sisotool.py
@@ -5,7 +5,7 @@
 from .timeresp import step_response
 from .lti import issiso, isdtime
 from .xferfcn import tf
-from .statesp import ss
+from .iosys import ss
 from .bdalg import append, connect
 from .iosys import tf2io, ss2io, summing_junction, interconnect
 from control.statesp import _convert_to_statespace, StateSpace
diff --git a/control/statesp.py b/control/statesp.py
@@ -62,8 +62,7 @@
 from . import config
 from copy import deepcopy
 
-__all__ = ['StateSpace', 'ss', 'rss', 'drss', 'tf2ss', 'ssdata']
-
+__all__ = ['StateSpace', 'tf2ss', 'ssdata']
 
 # Define module default parameter values
 _statesp_defaults = {
@@ -1768,7 +1767,7 @@ def _mimo2simo(sys, input, warn_conversion=False):
     return sys
 
 
-def ss(*args, **kwargs):
+def _ss(*args, **kwargs):
     """ss(A, B, C, D[, dt])
 
     Create a state space system.
@@ -1932,89 +1931,6 @@ def tf2ss(*args):
         raise ValueError("Needs 1 or 2 arguments; received %i." % len(args))
 
 
-def rss(states=1, outputs=1, inputs=1, strictly_proper=False):
-    """
-    Create a stable *continuous* random state space object.
-
-    Parameters
-    ----------
-    states : int
-        Number of state variables
-    outputs : int
-        Number of system outputs
-    inputs : int
-        Number of system inputs
-    strictly_proper : bool, optional
-        If set to 'True', returns a proper system (no direct term).
-
-    Returns
-    -------
-    sys : StateSpace
-        The randomly created linear system
-
-    Raises
-    ------
-    ValueError
-        if any input is not a positive integer
-
-    See Also
-    --------
-    drss
-
-    Notes
-    -----
-    If the number of states, inputs, or outputs is not specified, then the
-    missing numbers are assumed to be 1.  The poles of the returned system
-    will always have a negative real part.
-
-    """
-
-    return _rss_generate(states, inputs, outputs, 'c',
-                         strictly_proper=strictly_proper)
-
-
-def drss(states=1, outputs=1, inputs=1, strictly_proper=False):
-    """
-    Create a stable *discrete* random state space object.
-
-    Parameters
-    ----------
-    states : int
-        Number of state variables
-    inputs : integer
-        Number of system inputs
-    outputs : int
-        Number of system outputs
-    strictly_proper: bool, optional
-        If set to 'True', returns a proper system (no direct term).
-
-
-    Returns
-    -------
-    sys : StateSpace
-        The randomly created linear system
-
-    Raises
-    ------
-    ValueError
-        if any input is not a positive integer
-
-    See Also
-    --------
-    rss
-
-    Notes
-    -----
-    If the number of states, inputs, or outputs is not specified, then the
-    missing numbers are assumed to be 1.  The poles of the returned system
-    will always have a magnitude less than 1.
-
-    """
-
-    return _rss_generate(states, inputs, outputs, 'd',
-                         strictly_proper=strictly_proper)
-
-
 def ssdata(sys):
     """
     Return state space data objects for a system
diff --git a/control/tests/statesp_test.py b/control/tests/statesp_test.py
@@ -18,8 +18,9 @@
 from control.config import defaults
 from control.dtime import sample_system
 from control.lti import evalfr
-from control.statesp import (StateSpace, _convert_to_statespace, drss,
-                             rss, ss, tf2ss, _statesp_defaults, _rss_generate)
+from control.statesp import StateSpace, _convert_to_statespace, tf2ss, \
+    _statesp_defaults, _rss_generate
+from control.iosys import ss, rss, drss
 from control.tests.conftest import ismatarrayout, slycotonly
 from control.xferfcn import TransferFunction, ss2tf
 
diff --git a/control/tests/type_conversion_test.py b/control/tests/type_conversion_test.py
@@ -59,7 +59,7 @@ def sys_dict():
 rtype_list =           ['ss',  'tf', 'frd', 'lio', 'ios', 'arr', 'flt']
 conversion_table = [
     # op        left     ss     tf    frd    lio    ios    arr    flt
-    ('add',     'ss',  ['ss',  'ss',  'xrd', 'ss',  'xos', 'ss',  'ss' ]),
+    ('add',     'ss',  ['ss',  'ss',  'xrd', 'ss',  'ios', 'ss',  'ss' ]),
     ('add',     'tf',  ['tf',  'tf',  'xrd', 'tf',  'xos', 'tf',  'tf' ]),
     ('add',     'frd', ['xrd', 'xrd', 'frd', 'xrd', 'E',   'xrd', 'xrd']),
     ('add',     'lio', ['lio', 'lio', 'xrd', 'lio', 'ios', 'lio', 'lio']),
@@ -68,7 +68,7 @@ def sys_dict():
     ('add',     'flt', ['ss',  'tf',  'xrd', 'lio', 'ios', 'arr', 'flt']),
     
     # op        left     ss     tf    frd    lio    ios    arr    flt
-    ('sub',     'ss',  ['ss',  'ss',  'xrd', 'ss',  'xos', 'ss',  'ss' ]),
+    ('sub',     'ss',  ['ss',  'ss',  'xrd', 'ss',  'ios', 'ss',  'ss' ]),
     ('sub',     'tf',  ['tf',  'tf',  'xrd', 'tf',  'xos', 'tf',  'tf' ]),
     ('sub',     'frd', ['xrd', 'xrd', 'frd', 'xrd', 'E',   'xrd', 'xrd']),
     ('sub',     'lio', ['lio', 'lio', 'xrd', 'lio', 'ios', 'lio', 'lio']),
@@ -77,7 +77,7 @@ def sys_dict():
     ('sub',     'flt', ['ss',  'tf',  'xrd', 'lio', 'ios', 'arr', 'flt']),
     
     # op        left     ss     tf    frd    lio    ios    arr    flt
-    ('mul',     'ss',  ['ss',  'ss',  'xrd', 'ss',  'xos', 'ss',  'ss' ]),
+    ('mul',     'ss',  ['ss',  'ss',  'xrd', 'ss',  'ios', 'ss',  'ss' ]),
     ('mul',     'tf',  ['tf',  'tf',  'xrd', 'tf',  'xos', 'tf',  'tf' ]),
     ('mul',     'frd', ['xrd', 'xrd', 'frd', 'xrd', 'E',   'xrd', 'frd']),
     ('mul',     'lio', ['lio', 'lio', 'xrd', 'lio', 'ios', 'lio', 'lio']),
diff --git a/control/tests/xferfcn_test.py b/control/tests/xferfcn_test.py
@@ -8,14 +8,11 @@
 import operator
 
 import control as ct
-from control.statesp import StateSpace, _convert_to_statespace, rss
-from control.xferfcn import TransferFunction, _convert_to_transfer_function, \
-    ss2tf
-from control.lti import evalfr
+from control import StateSpace, TransferFunction, rss, ss2tf, evalfr
+from control import isctime, isdtime, sample_system, defaults
+from control.statesp import _convert_to_statespace
+from control.xferfcn import _convert_to_transfer_function
 from control.tests.conftest import slycotonly, nopython2, matrixfilter
-from control.lti import isctime, isdtime
-from control.dtime import sample_system
-from control.config import defaults
 
 
 class TestXferFcn:
