additional fixes for github actions warnings

murrayrm · murrayrm · commit 76dee0daa391 · 2023-12-29T15:44:58.000-08:00
diff --git a/control/optimal.py b/control/optimal.py
@@ -956,7 +956,7 @@ def solve_ocp(
         transpose=None, return_states=True, print_summary=True, log=False,
         **kwargs):
 
-    """Compute the solution to an optimal control problem.
+    r"""Compute the solution to an optimal control problem.
 
     The optimal trajectory (states and inputs) is computed so as to
     approximately mimimize a cost function of the following form (for
diff --git a/control/stochsys.py b/control/stochsys.py
@@ -183,14 +183,14 @@ def lqe(*args, **kwargs):
 
 # contributed by Sawyer B. Fuller <minster@uw.edu>
 def dlqe(*args, **kwargs):
-    """dlqe(A, G, C, QN, RN, [, N])
+    r"""dlqe(A, G, C, QN, RN, [, N])
 
     Linear quadratic estimator design (Kalman filter) for discrete-time
     systems. Given the system
 
     .. math::
 
-        x[n+1] &= Ax[n] + Bu[n] + Gw[n] \\\\
+        x[n+1] &= Ax[n] + Bu[n] + Gw[n] \\
         y[n] &= Cx[n] + Du[n] + v[n]
 
     with unbiased process noise w and measurement noise v with covariances
diff --git a/control/xferfcn.py b/control/xferfcn.py
@@ -468,7 +468,13 @@ def __str__(self, var=None):
                     numstr = _tf_polynomial_to_string(self.num[no][ni], var=var)
                     denstr = _tf_polynomial_to_string(self.den[no][ni], var=var)
                 elif self.display_format == 'zpk':
-                    z, p, k = tf2zpk(self.num[no][ni], self.den[no][ni])
+                    num = self.num[no][ni]
+                    if num.size == 1 and num.item() == 0:
+                        # Catch a special case taht SciPy doesn't handle
+                        z, p, k = tf2zpk([1.], self.den[no][ni])
+                        k = 0
+                    else:
+                        z, p, k = tf2zpk(self.num[no][ni], self.den[no][ni])
                     numstr = _tf_factorized_polynomial_to_string(
                         z, gain=k, var=var)
                     denstr = _tf_factorized_polynomial_to_string(p, var=var)
