new: center of gravity

src/scgenerator/spectra.py

@@ -125,8 +125,7 @@ class Spectrum(np.ndarray):
 
     @property
     def center_of_gravity(self):
-        intensity = self.time_int
-        return np.sum(intensity * self.t) / np.sum(intensity)
+        return pulse.center_of_gravity(self.t, self.time_int)
 
     def mask_wl(self, pos: float, width: float) -> Spectrum:
         """