Added discrete grid to pzmap function.

Victor · Victor · commit dc8410c04bbd · 2018-02-19T11:06:56.000+01:00
diff --git a/control/statesp.py b/control/statesp.py
@@ -460,10 +460,10 @@ def freqresp(self, omega):
         if isdtime(self, strict=True):
             dt = timebase(self)
             cmplx_freqs = exp(1.j * omega * dt)
-            if ((omega * dt).any() > pi):
+            if ((omega * dt).any() > math.pi):
                 warn_message = ("evalfr: frequency evaluation"
                                 " above Nyquist frequency")
-                warnings.warn(warn_message)
+                warn(warn_message)
         else:
             cmplx_freqs = omega * 1.j
 
