Update ufunc in MadArray and Waveform

madarrays/mad_array.py

@@ -98,6 +98,10 @@ def _complex_masking_only(f):
     return decorated
 
 
+UFUNC_RETURNING_MADARRAYS = ['add', 'subtract', 'multiply', 'true_divide',
+                             'floor_divide', 'floor', 'ceil', 'absolute']
+
+
 class MadArray(np.ndarray):
     """Subclass of numpy.ndarray to handle data with missing elements.
 
@@ -351,7 +355,7 @@ class MadArray(np.ndarray):
         new_results = []
         for result, output in zip(results, outputs):
             if output is None:
-                if not ufunc.__name__.startswith('is'):
+                if ufunc.__name__ in UFUNC_RETURNING_MADARRAYS:
                     new_results.append(np.asarray(result).view(MadArray))
                     new_results[-1]._mask = mask
                     new_results[-1]._complex_masking = complex_masking

madarrays/waveform.py

@@ -772,21 +772,9 @@ class Waveform(MadArray):
     def copy(self):
         return Waveform(self)
 
-    def __add__(self, other):
-        if isinstance(other, Waveform) and self.fs != other.fs:
-            errmsg = 'Waveforms do not have the same fs: {} and {}'
-            raise ValueError(errmsg.format(self.fs, other.fs))
-
-        return Waveform(super().__add__(other), fs=self.fs)
-
-    def __sub__(self, ma):
-        return self.__add__(-ma)
-
     def __eq__(self, other):
-        if isinstance(other, Waveform) and self.fs != other.fs:
-            errmsg = 'Waveforms do not have the same fs: {} and {}'
-            raise ValueError(errmsg.format(self.fs, other.fs))
-
+        # Test the compatability between Waveform
+        _ = self + other
         return super().__eq__(other)
 
     def is_equal(self, other):