Added missing module scope for warn in statesp.

jgoppert · cwrowley · commit 8d8a84d552bd · 2014-08-10T20:12:16.000-04:00
Signed-off-by: Clancy Rowley &lt;cwrowley@princeton.edu&gt;
diff --git a/src/statesp.py b/src/statesp.py
@@ -380,7 +380,7 @@ def evalfr(self, omega):
             dt = timebase(self)
             s = exp(1.j * omega * dt)
             if (omega * dt > pi):
-                warn("evalfr: frequency evaluation above Nyquist frequency")
+                warnings.warn("evalfr: frequency evaluation above Nyquist frequency")
         else:
             s = omega * 1.j
 
