Fix ruff "unused value" warnings

murrayrm · Feb 3, 2025 · Jan 25, 2025 · Feb 1, 2025 · Feb 1, 2025 · Feb 1, 2025
commit 7668d2c70db297f93f7e9a3829d339c4e2b728e7
diff --git a/control/freqplot.py b/control/freqplot.py
@@ -759,13 +759,11 @@ def _make_line_label(response, output_index, input_index):
             if plot_magnitude:
                 ax_mag.axhline(y=0 if dB else 1, color='k', linestyle=':',
                                zorder=-20)
-                mag_ylim = ax_mag.get_ylim()
 
             if plot_phase:
                 ax_phase.axhline(y=phase_limit if deg else
                                  math.radians(phase_limit),
                                  color='k', linestyle=':', zorder=-20)
-                phase_ylim = ax_phase.get_ylim()
 
             # Annotate the phase margin (if it exists)
             if plot_phase and pm != float('inf') and Wcp != float('nan'):

diff --git a/control/modelsimp.py b/control/modelsimp.py
@@ -340,7 +340,7 @@ def balanced_reduction(sys, orders, method='truncate', alpha=None):
 
     # check if orders is a list or a scalar
     try:
-        order = iter(orders)
+        iter(orders)
     except TypeError:           # if orders is a scalar
         orders = [orders]
 

diff --git a/control/nlsys.py b/control/nlsys.py
@@ -210,7 +210,7 @@ def __mul__(self, other):
                 "can't multiply systems with incompatible inputs and outputs")
 
         # Make sure timebase are compatible
-        dt = common_timebase(other.dt, self.dt)
+        common_timebase(other.dt, self.dt)
 
         # Create a new system to handle the composition
         inplist = [(0, i) for i in range(other.ninputs)]
@@ -242,7 +242,7 @@ def __rmul__(self, other):
                              "inputs and outputs")
 
         # Make sure timebase are compatible
-        dt = common_timebase(self.dt, other.dt)
+        common_timebase(self.dt, other.dt)
 
         # Create a new system to handle the composition
         inplist = [(0, i) for i in range(self.ninputs)]

diff --git a/control/phaseplot.py b/control/phaseplot.py
@@ -161,7 +161,6 @@ def phase_plane_plot(
 
     # Create copy of kwargs for later checking to find unused arguments
     initial_kwargs = dict(kwargs)
-    passed_kwargs = False
 
     # Utility function to create keyword arguments
     def _create_kwargs(global_kwargs, local_kwargs, **other_kwargs):
@@ -1143,10 +1142,11 @@ def phase_plot(odefun, X=None, Y=None, scale=1, X0=None, T=None,
         if scale is None:
             plt.quiver(x1, x2, dx[:,:,1], dx[:,:,2], angles='xy')
         elif (scale != 0):
+            plt.quiver(x1, x2, dx[:,:,0]*np.abs(scale),
+                       dx[:,:,1]*np.abs(scale), angles='xy')
             #! TODO: optimize parameters for arrows
             #! TODO: figure out arguments to make arrows show up correctly
-            xy = plt.quiver(x1, x2, dx[:,:,0]*np.abs(scale),
-                            dx[:,:,1]*np.abs(scale), angles='xy')
+            # xy = plt.quiver(...)
             # set(xy, 'LineWidth', PP_arrow_linewidth, 'Color', 'b')
 
         #! TODO: Tweak the shape of the plot
@@ -1256,15 +1256,17 @@ def phase_plot(odefun, X=None, Y=None, scale=1, X0=None, T=None,
         #! TODO: figure out arguments to make arrows show up correctly
         plt.quiver(x1, x2, dx[:,:,0], dx[:,:,1], angles='xy')
     elif scale != 0 and Narrows > 0:
+        plt.quiver(x1, x2, dx[:,:,0]*abs(scale), dx[:,:,1]*abs(scale),
+                   angles='xy')
         #! TODO: figure out arguments to make arrows show up correctly
-        xy = plt.quiver(x1, x2, dx[:,:,0]*abs(scale), dx[:,:,1]*abs(scale),
-                        angles='xy')
+        # xy = plt.quiver(...)
         # set(xy, 'LineWidth', PP_arrow_linewidth)
         # set(xy, 'AutoScale', 'off')
         # set(xy, 'AutoScaleFactor', 0)
 
     if scale < 0:
-        bp = plt.plot(x1, x2, 'b.');        # add dots at base
+        plt.plot(x1, x2, 'b.');        # add dots at base
+        # bp = plt.plot(...)
         # set(bp, 'MarkerSize', PP_arrow_markersize)
 
 

diff --git a/control/stochsys.py b/control/stochsys.py
@@ -166,12 +166,14 @@ def lqe(*args, **kwargs):
 
     # Get the cross-covariance matrix, if given
     if (len(args) > index + 2):
-        NN = np.array(args[index+2], ndmin=2, dtype=float)
+        # NN = np.array(args[index+2], ndmin=2, dtype=float)
         raise ControlNotImplemented("cross-covariance not implemented")
 
     else:
+        pass
         # For future use (not currently used below)
-        NN = np.zeros((QN.shape[0], RN.shape[1]))
+        # NN = np.zeros((QN.shape[0], RN.shape[1]))
+
 
     # Check dimensions of G (needed before calling care())
     _check_shape("QN", QN, G.shape[1], G.shape[1])
@@ -290,7 +292,7 @@ def dlqe(*args, **kwargs):
     #    NN = np.zeros(QN.size(0),RN.size(1))
     # NG = G @ NN
     if len(args) > index + 2:
-        NN = np.array(args[index+2], ndmin=2, dtype=float)
+        # NN = np.array(args[index+2], ndmin=2, dtype=float)
         raise ControlNotImplemented("cross-covariance not yet implememented")
 
     # Check dimensions of G (needed before calling care())

diff --git a/control/xferfcn.py b/control/xferfcn.py
@@ -1503,7 +1503,6 @@ def _convert_to_transfer_function(
 
     """
     from .statesp import StateSpace
-    kwargs = {}
 
     if isinstance(sys, TransferFunction):
         return sys