Merge pull request #515 from murrayrm/input_output_to_ninput_noutput

Switch LTI class and subclasses to use ninputs, noutputs, nstates

control/bdalg.py

@@ -76,7 +76,7 @@ def series(sys1, *sysn):
     Raises
     ------
     ValueError
-        if `sys2.inputs` does not equal `sys1.outputs`
+        if `sys2.ninputs` does not equal `sys1.noutputs`
         if `sys1.dt` is not compatible with `sys2.dt`
 
     See Also
@@ -336,25 +336,25 @@ def connect(sys, Q, inputv, outputv):
     """
     inputv, outputv, Q = np.asarray(inputv), np.asarray(outputv), np.asarray(Q)
     # check indices
-    index_errors = (inputv - 1 > sys.inputs) | (inputv < 1)
+    index_errors = (inputv - 1 > sys.ninputs) | (inputv < 1)
     if np.any(index_errors):
         raise IndexError(
             "inputv index %s out of bounds" % inputv[np.where(index_errors)])
-    index_errors = (outputv - 1 > sys.outputs) | (outputv < 1)
+    index_errors = (outputv - 1 > sys.noutputs) | (outputv < 1)
     if np.any(index_errors):
         raise IndexError(
             "outputv index %s out of bounds" % outputv[np.where(index_errors)])
-    index_errors = (Q[:,0:1] - 1 > sys.inputs) | (Q[:,0:1] < 1)
+    index_errors = (Q[:,0:1] - 1 > sys.ninputs) | (Q[:,0:1] < 1)
     if np.any(index_errors):
         raise IndexError(
             "Q input index %s out of bounds" % Q[np.where(index_errors)])
-    index_errors = (np.abs(Q[:,1:]) - 1 > sys.outputs)
+    index_errors = (np.abs(Q[:,1:]) - 1 > sys.noutputs)
     if np.any(index_errors):
         raise IndexError(
             "Q output index %s out of bounds" % Q[np.where(index_errors)])
 
     # first connect
-    K = np.zeros((sys.inputs, sys.outputs))
+    K = np.zeros((sys.ninputs, sys.noutputs))
     for r in np.array(Q).astype(int):
         inp = r[0]-1
         for outp in r[1:]:
@@ -365,8 +365,8 @@ def connect(sys, Q, inputv, outputv):
     sys = sys.feedback(np.array(K), sign=1)
 
     # now trim
-    Ytrim = np.zeros((len(outputv), sys.outputs))
-    Utrim = np.zeros((sys.inputs, len(inputv)))
+    Ytrim = np.zeros((len(outputv), sys.noutputs))
+    Utrim = np.zeros((sys.ninputs, len(inputv)))
     for i,u in enumerate(inputv):
         Utrim[u-1,i] = 1.
     for i,y in enumerate(outputv):

control/canonical.py

@@ -79,24 +79,24 @@ def reachable_form(xsys):
     zsys.B[0, 0] = 1.0
     zsys.A = zeros_like(xsys.A)
     Apoly = poly(xsys.A)                # characteristic polynomial
-    for i in range(0, xsys.states):
+    for i in range(0, xsys.nstates):
         zsys.A[0, i] = -Apoly[i+1] / Apoly[0]
-        if (i+1 < xsys.states):
+        if (i+1 < xsys.nstates):
             zsys.A[i+1, i] = 1.0
 
     # Compute the reachability matrices for each set of states
     Wrx = ctrb(xsys.A, xsys.B)
     Wrz = ctrb(zsys.A, zsys.B)
 
-    if matrix_rank(Wrx) != xsys.states:
+    if matrix_rank(Wrx) != xsys.nstates:
         raise ValueError("System not controllable to working precision.")
 
     # Transformation from one form to another
     Tzx = solve(Wrx.T, Wrz.T).T  # matrix right division, Tzx = Wrz * inv(Wrx)
 
     # Check to make sure inversion was OK.  Note that since we are inverting
     # Wrx and we already checked its rank, this exception should never occur
-    if matrix_rank(Tzx) != xsys.states:         # pragma: no cover
+    if matrix_rank(Tzx) != xsys.nstates:         # pragma: no cover
         raise ValueError("Transformation matrix singular to working precision.")
 
     # Finally, compute the output matrix
@@ -133,9 +133,9 @@ def observable_form(xsys):
     zsys.C[0, 0] = 1
     zsys.A = zeros_like(xsys.A)
     Apoly = poly(xsys.A)                # characteristic polynomial
-    for i in range(0, xsys.states):
+    for i in range(0, xsys.nstates):
         zsys.A[i, 0] = -Apoly[i+1] / Apoly[0]
-        if (i+1 < xsys.states):
+        if (i+1 < xsys.nstates):
             zsys.A[i, i+1] = 1
 
     # Compute the observability matrices for each set of states
@@ -145,7 +145,7 @@ def observable_form(xsys):
     # Transformation from one form to another
     Tzx = solve(Wrz, Wrx)  # matrix left division, Tzx = inv(Wrz) * Wrx
 
-    if matrix_rank(Tzx) != xsys.states:
+    if matrix_rank(Tzx) != xsys.nstates:
         raise ValueError("Transformation matrix singular to working precision.")
 
     # Finally, compute the output matrix

control/frdata.py

@@ -155,11 +155,11 @@ def __init__(self, *args, **kwargs):
     def __str__(self):
         """String representation of the transfer function."""
 
-        mimo = self.inputs > 1 or self.outputs > 1
+        mimo = self.ninputs > 1 or self.noutputs > 1
         outstr = ['Frequency response data']
 
-        for i in range(self.inputs):
-            for j in range(self.outputs):
+        for i in range(self.ninputs):
+            for j in range(self.noutputs):
                 if mimo:
                     outstr.append("Input %i to output %i:" % (i + 1, j + 1))
                 outstr.append('Freq [rad/s]  Response')
@@ -201,12 +201,12 @@ def __add__(self, other):
         other = _convert_to_FRD(other, omega=self.omega)
 
         # Check that the input-output sizes are consistent.
-        if self.inputs != other.inputs:
+        if self.ninputs != other.ninputs:
             raise ValueError("The first summand has %i input(s), but the \
-second has %i." % (self.inputs, other.inputs))
-        if self.outputs != other.outputs:
+second has %i." % (self.ninputs, other.ninputs))
+        if self.noutputs != other.noutputs:
             raise ValueError("The first summand has %i output(s), but the \
-second has %i." % (self.outputs, other.outputs))
+second has %i." % (self.noutputs, other.noutputs))
 
         return FRD(self.fresp + other.fresp, other.omega)
 
@@ -236,14 +236,14 @@ def __mul__(self, other):
             other = _convert_to_FRD(other, omega=self.omega)
 
         # Check that the input-output sizes are consistent.
-        if self.inputs != other.outputs:
+        if self.ninputs != other.noutputs:
             raise ValueError(
                 "H = G1*G2: input-output size mismatch: "
                 "G1 has %i input(s), G2 has %i output(s)." %
-                (self.inputs, other.outputs))
+                (self.ninputs, other.noutputs))
 
-        inputs = other.inputs
-        outputs = self.outputs
+        inputs = other.ninputs
+        outputs = self.noutputs
         fresp = empty((outputs, inputs, len(self.omega)),
                       dtype=self.fresp.dtype)
         for i in range(len(self.omega)):
@@ -263,14 +263,14 @@ def __rmul__(self, other):
             other = _convert_to_FRD(other, omega=self.omega)
 
         # Check that the input-output sizes are consistent.
-        if self.outputs != other.inputs:
+        if self.noutputs != other.ninputs:
             raise ValueError(
                 "H = G1*G2: input-output size mismatch: "
                 "G1 has %i input(s), G2 has %i output(s)." %
-                (other.inputs, self.outputs))
+                (other.ninputs, self.noutputs))
 
-        inputs = self.inputs
-        outputs = other.outputs
+        inputs = self.ninputs
+        outputs = other.noutputs
 
         fresp = empty((outputs, inputs, len(self.omega)),
                       dtype=self.fresp.dtype)
@@ -290,8 +290,8 @@ def __truediv__(self, other):
         else:
             other = _convert_to_FRD(other, omega=self.omega)
 
-        if (self.inputs > 1 or self.outputs > 1 or
-            other.inputs > 1 or other.outputs > 1):
+        if (self.ninputs > 1 or self.noutputs > 1 or
+            other.ninputs > 1 or other.noutputs > 1):
             raise NotImplementedError(
                 "FRD.__truediv__ is currently only implemented for SISO "
                 "systems.")
@@ -313,8 +313,8 @@ def __rtruediv__(self, other):
         else:
             other = _convert_to_FRD(other, omega=self.omega)
 
-        if (self.inputs > 1 or self.outputs > 1 or
-            other.inputs > 1 or other.outputs > 1):
+        if (self.ninputs > 1 or self.noutputs > 1 or
+            other.ninputs > 1 or other.noutputs > 1):
             raise NotImplementedError(
                 "FRD.__rtruediv__ is currently only implemented for "
                 "SISO systems.")
@@ -392,10 +392,10 @@ def eval(self, omega, squeeze=None):
             else:
                 out = self.fresp[:, :, elements]
         else:
-            out = empty((self.outputs, self.inputs, len(omega_array)),
+            out = empty((self.noutputs, self.ninputs, len(omega_array)),
                          dtype=complex)
-            for i in range(self.outputs):
-                for j in range(self.inputs):
+            for i in range(self.noutputs):
+                for j in range(self.ninputs):
                     for k, w in enumerate(omega_array):
                         frraw = splev(w, self.ifunc[i, j], der=0)
                         out[i, j, k] = frraw[0] + 1.0j * frraw[1]
@@ -406,7 +406,7 @@ def __call__(self, s, squeeze=None):
         """Evaluate system's transfer function at complex frequencies.
 
         Returns the complex frequency response `sys(s)` of system `sys` with
-        `m = sys.inputs` number of inputs and `p = sys.outputs` number of
+        `m = sys.ninputs` number of inputs and `p = sys.noutputs` number of
         outputs.
 
         To evaluate at a frequency omega in radians per second, enter
@@ -474,10 +474,10 @@ def feedback(self, other=1, sign=-1):
 
         other = _convert_to_FRD(other, omega=self.omega)
 
-        if (self.outputs != other.inputs or self.inputs != other.outputs):
+        if (self.noutputs != other.ninputs or self.ninputs != other.noutputs):
             raise ValueError(
                 "FRD.feedback, inputs/outputs mismatch")
-        fresp = empty((self.outputs, self.inputs, len(other.omega)),
+        fresp = empty((self.noutputs, self.ninputs, len(other.omega)),
                       dtype=complex)
         # TODO: vectorize this
         # TODO: handle omega re-mapping
@@ -487,9 +487,9 @@ def feedback(self, other=1, sign=-1):
             fresp[:, :, k] = np.dot(
                 self.fresp[:, :, k],
                 linalg.solve(
-                    eye(self.inputs)
+                    eye(self.ninputs)
                     + np.dot(other.fresp[:, :, k], self.fresp[:, :, k]),
-                    eye(self.inputs))
+                    eye(self.ninputs))
             )
 
         return FRD(fresp, other.omega, smooth=(self.ifunc is not None))

control/freqplot.py

@@ -214,7 +214,7 @@ def bode_plot(syslist, omega=None,
 
     mags, phases, omegas, nyquistfrqs = [], [], [], []
     for sys in syslist:
-        if sys.inputs > 1 or sys.outputs > 1:
+        if sys.ninputs > 1 or sys.noutputs > 1:
             # TODO: Add MIMO bode plots.
             raise NotImplementedError(
                 "Bode is currently only implemented for SISO systems.")
@@ -582,7 +582,7 @@ def nyquist_plot(syslist, omega=None, plot=True, label_freq=0,
                             num=50, endpoint=True, base=10.0)
 
     for sys in syslist:
-        if sys.inputs > 1 or sys.outputs > 1:
+        if sys.ninputs > 1 or sys.noutputs > 1:
             # TODO: Add MIMO nyquist plots.
             raise NotImplementedError(
                 "Nyquist is currently only implemented for SISO systems.")
@@ -672,7 +672,7 @@ def gangof4_plot(P, C, omega=None, **kwargs):
     -------
     None
     """
-    if P.inputs > 1 or P.outputs > 1 or C.inputs > 1 or C.outputs > 1:
+    if P.ninputs > 1 or P.noutputs > 1 or C.ninputs > 1 or C.noutputs > 1:
         # TODO: Add MIMO go4 plots.
         raise NotImplementedError(
             "Gang of four is currently only implemented for SISO systems.")

control/iosys.py

@@ -659,25 +659,25 @@ def __init__(self, linsys, inputs=None, outputs=None, states=None,
 
         # Create the I/O system object
         super(LinearIOSystem, self).__init__(
-            inputs=linsys.inputs, outputs=linsys.outputs,
-            states=linsys.states, params={}, dt=linsys.dt, name=name)
+            inputs=linsys.ninputs, outputs=linsys.noutputs,
+            states=linsys.nstates, params={}, dt=linsys.dt, name=name)
 
         # Initalize additional state space variables
         StateSpace.__init__(self, linsys, remove_useless=False)
 
         # Process input, output, state lists, if given
         # Make sure they match the size of the linear system
         ninputs, self.input_index = self._process_signal_list(
-            inputs if inputs is not None else linsys.inputs, prefix='u')
-        if ninputs is not None and linsys.inputs != ninputs:
+            inputs if inputs is not None else linsys.ninputs, prefix='u')
+        if ninputs is not None and linsys.ninputs != ninputs:
             raise ValueError("Wrong number/type of inputs given.")
         noutputs, self.output_index = self._process_signal_list(
-            outputs if outputs is not None else linsys.outputs, prefix='y')
-        if noutputs is not None and linsys.outputs != noutputs:
+            outputs if outputs is not None else linsys.noutputs, prefix='y')
+        if noutputs is not None and linsys.noutputs != noutputs:
             raise ValueError("Wrong number/type of outputs given.")
         nstates, self.state_index = self._process_signal_list(
-            states if states is not None else linsys.states, prefix='x')
-        if nstates is not None and linsys.states != nstates:
+            states if states is not None else linsys.nstates, prefix='x')
+        if nstates is not None and linsys.nstates != nstates:
             raise ValueError("Wrong number/type of states given.")
 
     def _update_params(self, params={}, warning=True):
@@ -1345,9 +1345,9 @@ def __init__(self, io_sys, ss_sys=None):
         # Initialize the state space attributes
         if isinstance(ss_sys, StateSpace):
             # Make sure the dimension match
-            if io_sys.ninputs != ss_sys.inputs or \
-               io_sys.noutputs != ss_sys.outputs or \
-               io_sys.nstates != ss_sys.states:
+            if io_sys.ninputs != ss_sys.ninputs or \
+               io_sys.noutputs != ss_sys.noutputs or \
+               io_sys.nstates != ss_sys.nstates:
                 raise ValueError("System dimensions for first and second "
                                  "arguments must match.")
             StateSpace.__init__(self, ss_sys, remove_useless=False)

control/lti.py

@@ -47,10 +47,46 @@ def __init__(self, inputs=1, outputs=1, dt=None):
         """Assign the LTI object's numbers of inputs and ouputs."""
 
         # Data members common to StateSpace and TransferFunction.
-        self.inputs = inputs
-        self.outputs = outputs
+        self.ninputs = inputs
+        self.noutputs = outputs
         self.dt = dt
 
+    #
+    # Getter and setter functions for legacy state attributes
+    #
+    # For this iteration, generate a deprecation warning whenever the
+    # getter/setter is called.  For a future iteration, turn it into a
+    # future warning, so that users will see it.
+    #
+
+    @property
+    def inputs(self):
+        warn("The LTI `inputs` attribute will be deprecated in a future "
+             "release.  Use `ninputs` instead.",
+             DeprecationWarning, stacklevel=2)
+        return self.ninputs
+
+    @inputs.setter
+    def inputs(self, value):
+        warn("The LTI `inputs` attribute will be deprecated in a future "
+             "release.  Use `ninputs` instead.",
+             DeprecationWarning, stacklevel=2)
+        self.ninputs = value
+
+    @property
+    def outputs(self):
+        warn("The LTI `outputs` attribute will be deprecated in a future "
+             "release.  Use `noutputs` instead.",
+             DeprecationWarning, stacklevel=2)
+        return self.noutputs
+
+    @outputs.setter
+    def outputs(self, value):
+        warn("The LTI `outputs` attribute will be deprecated in a future "
+             "release.  Use `noutputs` instead.",
+             DeprecationWarning, stacklevel=2)
+        self.noutputs = value
+
     def isdtime(self, strict=False):
         """
         Check to see if a system is a discrete-time system
@@ -88,7 +124,7 @@ def isctime(self, strict=False):
 
     def issiso(self):
         '''Check to see if a system is single input, single output'''
-        return self.inputs == 1 and self.outputs == 1
+        return self.ninputs == 1 and self.noutputs == 1
 
     def damp(self):
         '''Natural frequency, damping ratio of system poles
@@ -126,7 +162,7 @@ def frequency_response(self, omega, squeeze=None):
              G(exp(j*omega*dt)) = mag*exp(j*phase).
 
         In general the system may be multiple input, multiple output (MIMO),
-        where `m = self.inputs` number of inputs and `p = self.outputs` number
+        where `m = self.ninputs` number of inputs and `p = self.noutputs` number
         of outputs.
 
         Parameters
@@ -475,7 +511,7 @@ def evalfr(sys, x, squeeze=None):
 
     Returns the complex frequency response `sys(x)` where `x` is `s` for
     continuous-time systems and `z` for discrete-time systems, with
-    `m = sys.inputs` number of inputs and `p = sys.outputs` number of
+    `m = sys.ninputs` number of inputs and `p = sys.noutputs` number of
     outputs.
 
     To evaluate at a frequency omega in radians per second, enter
@@ -532,7 +568,7 @@ def freqresp(sys, omega, squeeze=None):
     """Frequency response of an LTI system at multiple angular frequencies.
 
     In general the system may be multiple input, multiple output (MIMO), where
-    `m = sys.inputs` number of inputs and `p = sys.outputs` number of
+    `m = sys.ninputs` number of inputs and `p = sys.noutputs` number of
     outputs.
 
     Parameters