move copy to base class, fix docstrings, work on iter_evoked

mne/time_frequency/spectrogram.py

@@ -392,7 +392,7 @@ def apply_baseline(self, baseline, mode, verbose):
 
         Returns
         -------
-        inst : instance of AverageTFR
+        inst : instance of RawTFR, EpochsTFR, or AverageTFR
             The modified instance.
         """
         self.baseline = _check_baseline(
@@ -401,6 +401,16 @@ def apply_baseline(self, baseline, mode, verbose):
         rescale(self.data, self.times, self.baseline, mode, copy=False)
         return self
 
+    def copy(self):
+        """Return copy of the TFR instance.
+
+        Returns
+        -------
+        inst : instance of RawTFR, EpochsTFR, or AverageTFR
+            A copy of the object.
+        """
+        return deepcopy(self)
+
     def crop(self, tmin=None, tmax=None, fmin=None, fmax=None, include_tmax=True):
         """Crop data to a given time interval in place.
 
@@ -422,7 +432,7 @@ def crop(self, tmin=None, tmax=None, fmin=None, fmax=None, include_tmax=True):
 
         Returns
         -------
-        inst : instance of AverageTFR
+        inst : instance of RawTFR, EpochsTFR, or AverageTFR
             The modified instance.
         """
         super().crop(tmin=tmin, tmax=tmax, include_tmax=include_tmax)
@@ -928,16 +938,6 @@ def _get_instance_data(self, reject_by_annotation):
         # prepend a singleton "epochs" axis
         return data[np.newaxis]
 
-    def copy(self):
-        """Return copy of the RawTFR instance.
-
-        Returns
-        -------
-        RawTFR : instance of RawTFR
-            A copy of the object.
-        """
-        return deepcopy(self)
-
 
 class EpochsTFR(BaseTFR, GetEpochsMixin):
     """Data object for spectrotemporal representations of epoched data.
@@ -1125,14 +1125,14 @@ def iter_evoked(self, copy=False):
         while True:
             try:
                 data = self.__next__()
-            except StopIteration:
+            except StopIteration:  # TODO this is never raised
                 break
             if copy:
                 state["info"] = deepcopy(self.info)
                 state["data"] = data.copy()
             else:
                 state["data"] = data
-            yield AverageTFR(state)
+            yield AverageTFR(state, method=None, freqs=None)
 
     def plot(self):
         """Plot EpochsTFR as a 2D image."""
@@ -1226,9 +1226,6 @@ def __init__(
             **method_kw,
         )
 
-        # TODO are there other properties of `inst` we should propagate here?
-        self._nave = inst.nave
-
     @property
     def nave(self):
         return self._nave