Fixed ntains definition in calibrateTIM()

xgm.py

@@ -478,6 +478,7 @@ def calibrateTIM(data, rollingWindow=200, mcp=1, plot=False, use_apd=True, intst
     start = 0
     stop = None
     npulses = data['npulses_sase3']
+    ntrains = npulses.shape[0]
     if not np.all(npulses == npulses[0]):
         start = np.argmax(npulses.values)
         stop = ntrains + np.argmax(npulses.values[::-1]) - 1