Catch arctan2 errors

src/sinefit.py

@@ -172,7 +172,11 @@ def sfit4(data, fs):
     ## Extract results
     A = sqrt(s[0]*s[0] + s[1]*s[1]) # eqn B.21
     f0 = w / (2*pi)
-    phi = -arctan2(s[1], s[0]) # eqn B.22
+    try:
+        phi = -arctan2(s[1], s[0]) # eqn B.22
+    except TypeError:
+        # something broke down, just return zeros
+        return (0, 0, 0, 0)
     C = s[2]
 
     return (A, f0, phi, C)