fix(dataloader): selects groups in passed df

src/wela/dataloader.py

@@ -651,7 +651,9 @@ class dataloader:
                 print(group, "not recognised")
                 return None, None
         else:
-            wdf = df.pivot(columns="time", index="id", values=signal)
+            wdf = df[df.group == group].pivot(
+                columns="time", index="id", values=signal
+            )
         time = wdf.columns.to_numpy()
         # each column is a time series
         values = wdf.to_numpy()