Fix Notebooks (#4)

* fix cdip

* D3D TRTS eg fix

* fix pylint error

* pylint

* fix too many branches

Author: ssolson

examples/ADCP_Delft3D_TRTS_example.ipynb

@@ -241,6 +241,7 @@ def short_term_extreme(
         short_term_extreme_dist = fit_maxima(maxima)
     else:
         print("Passed `method` not found.")
+        short_term_extreme_dist = None
     return short_term_extreme_dist
 
 

examples/cdip_example.ipynb

@@ -107,6 +107,8 @@ def harmonics(
         hertz = np.arange(0, 3060, 5)
     elif grid_freq == 50:
         hertz = np.arange(0, 2570, 5)
+    else:
+        raise ValueError(f"grid_freq must be either 50 or 60. Got {grid_freq}")
 
     harmonic_amplitudes = harmonic_amplitudes.reindex(
         {"frequency": hertz}, method="nearest"
@@ -322,7 +324,11 @@ def interharmonics(
             + f"xr.DataArray, or xr.Dataset. Got {type(harmonic_amplitudes)}"
         )
 
-    if grid_freq not in [50, 60]:
+    if grid_freq == 60:
+        hertz = np.arange(0, 3060, 60)
+    elif grid_freq == 50:
+        hertz = np.arange(0, 2550, 50)
+    else:
         raise ValueError(f"grid_freq must be either 50 or 60. Got {grid_freq}")
 
     if not isinstance(to_pandas, bool):
@@ -340,11 +346,6 @@ def interharmonics(
             + f"of harmonic_amplitudes. Got {frequency_dimension}"
         )
 
-    if grid_freq == 60:
-        hertz = np.arange(0, 3060, 60)
-    elif grid_freq == 50:
-        hertz = np.arange(0, 2550, 50)
-
     # Sort input data index
     if frequency_dimension == "":
         frequency_dimension = list(harmonic_amplitudes.dims)[0]