evalfr(sys,s) -> sys(s); mimo errors specified as ControlMIMONotImplemented in a few places

sawyerbfuller · sawyerbfuller · commit ee6a72e638ef · 2021-01-28T14:07:58.000-08:00
diff --git a/control/freqplot.py b/control/freqplot.py
@@ -50,6 +50,7 @@
 from .ctrlutil import unwrap
 from .bdalg import feedback
 from .margins import stability_margins
+from .exception import ControlMIMONotImplemented
 from . import config
 
 __all__ = ['bode_plot', 'nyquist_plot', 'gangof4_plot',
@@ -214,9 +215,9 @@ def bode_plot(syslist, omega=None,
 
     mags, phases, omegas, nyquistfrqs = [], [], [], []
     for sys in syslist:
-        if sys.ninputs > 1 or sys.noutputs > 1:
+        if not sys.issiso():
             # TODO: Add MIMO bode plots.
-            raise NotImplementedError(
+            raise ControlMIMONotImplemented(
                 "Bode is currently only implemented for SISO systems.")
         else:
             omega_sys = np.array(omega)
@@ -582,9 +583,9 @@ def nyquist_plot(syslist, omega=None, plot=True, label_freq=0,
                             num=50, endpoint=True, base=10.0)
 
     for sys in syslist:
-        if sys.ninputs > 1 or sys.noutputs > 1:
+        if not sys.issiso():
             # TODO: Add MIMO nyquist plots.
-            raise NotImplementedError(
+            raise ControlMIMONotImplemented(
                 "Nyquist is currently only implemented for SISO systems.")
         else:
             # Get the magnitude and phase of the system
@@ -672,9 +673,9 @@ def gangof4_plot(P, C, omega=None, **kwargs):
     -------
     None
     """
-    if P.ninputs > 1 or P.noutputs > 1 or C.ninputs > 1 or C.noutputs > 1:
+    if not P.issiso() or not C.issiso():
         # TODO: Add MIMO go4 plots.
-        raise NotImplementedError(
+        raise ControlMIMONotImplemented(
             "Gang of four is currently only implemented for SISO systems.")
 
     # Get the default parameter values
diff --git a/control/margins.py b/control/margins.py
@@ -207,7 +207,7 @@ def fun(wdt):
 
 
 # Took the framework for the old function by
-# Sawyer B. Fuller <minster@caltech.edu>, removed a lot of the innards
+# Sawyer B. Fuller <minster@uw.edu>, removed a lot of the innards
 # and replaced with analytical polynomial functions for LTI systems.
 #
 # idea for the frequency data solution copied/adapted from
@@ -294,29 +294,29 @@ def stability_margins(sysdata, returnall=False, epsw=0.0):
             # frequency for gain margin: phase crosses -180 degrees
             w_180 = _poly_iw_real_crossing(num_iw, den_iw, epsw)
             with np.errstate(all='ignore'):  # den=0 is okay
-                w180_resp = evalfr(sys, 1J * w_180)
+                w180_resp = sys(1J * w_180)
 
             # frequency for phase margin : gain crosses magnitude 1
             wc = _poly_iw_mag1_crossing(num_iw, den_iw, epsw)
-            wc_resp = evalfr(sys, 1J * wc)
+            wc_resp = sys(1J * wc)
 
             # stability margin
             wstab = _poly_iw_wstab(num_iw, den_iw, epsw)
-            ws_resp = evalfr(sys, 1J * wstab)
+            ws_resp = sys(1J * wstab)
 
         else:  # Discrete Time
             zargs = _poly_z_invz(sys)
             # gain margin
             z, w_180 = _poly_z_real_crossing(*zargs, epsw=epsw)
-            w180_resp = evalfr(sys, z)
+            w180_resp = sys(z)
 
             # phase margin
             z, wc = _poly_z_mag1_crossing(*zargs, epsw=epsw)
-            wc_resp = evalfr(sys, z)
+            wc_resp = sys(z)
 
             # stability margin
             z, wstab = _poly_z_wstab(*zargs, epsw=epsw)
-            ws_resp = evalfr(sys, z)
+            ws_resp = sys(z)
 
         # only keep frequencies where the negative real axis is crossed
         w_180 = w_180[w180_resp <= 0.]
