Fix volume difference percent when difference equal to zero

src/analysis/observed_storm_impacts.py

@@ -154,12 +154,16 @@ def volume_change(df_profiles, df_profile_features, zone):
         if np.isnan(diff_vol):
             diff_vol = 0
 
+        # Base pct change on diff volume
+        if diff_vol == 0:
+            pct_change = 0
+        else:
+            pct_change = diff_vol / prestorm_vol * 100
+
         df_vol_changes.loc[site_id, "prestorm_{}_vol".format(zone)] = prestorm_vol
         df_vol_changes.loc[site_id, "poststorm_{}_vol".format(zone)] = poststorm_vol
         df_vol_changes.loc[site_id, "{}_vol_change".format(zone)] = diff_vol
-        df_vol_changes.loc[site_id, "{}_pct_change".format(zone)] = (
-            diff_vol / prestorm_vol * 100
-        )
+        df_vol_changes.loc[site_id, "{}_pct_change".format(zone)] = pct_change
 
     return df_vol_changes
 
@@ -255,6 +259,8 @@ def create_observed_impacts(
     df_raw_features = pd.read_csv(raw_profile_features_csv, index_col=[0])
     df_observed_impacts = overwrite_impacts(df_observed_impacts, df_raw_features)
 
+    # TODO Calculate change in slopes, shoreline and volume
+
     # Save dataframe to csv
     df_observed_impacts.to_csv(output_file, float_format="%.4f")