--- a/sitesurvey.py	Wed Sep 28 14:38:23 2011 +0930
+++ b/sitesurvey.py	Wed Sep 28 17:14:30 2011 +0930
@@ -88,8 +88,13 @@
         self.calgains = gains
 
         # Create interpolation function
-        self.interp = scipy.interpolate.interp1d(self.calfreqs, self.calgains, bound_error = True)
+        self._interp = scipy.interpolate.interp1d(self.calfreqs, self.calgains)
 
+    def interp(self, freqs):
+        if numpy.any(freqs < self.calfreqs[0]) or numpy.any(freqs > self.calfreqs[-1]):
+            raise exceptions.SyntaxError("Frequency out of range of calibration %f - %f" % (calfreqs[0], calfreqs[-1]))
+        return self._interp(freqs)
+        
 def getexpt(sequence):
     '''Given a sequence return the experiment which should be run next and how long until it should start'''