Issue/624 pv types (#641)

* assert the types we want of pv data - TDD

* change data types to float32 or int32

* tidy

Co-authored-by: Jacob Bieker <jacob@bieker.tech>

Author: peterdudfield

nowcasting_dataset/data_sources/pv/pv_data_source.py

@@ -396,14 +396,17 @@ def get_example(self, location: SpaceTimeLocation) -> xr.Dataset:
             data=pv_system_row_number,
             dims=["id"],
         )
-        pv["x_osgb"] = x_coords
-        pv["y_osgb"] = y_coords
+        pv["x_osgb"] = x_coords.astype("float32")
+        pv["y_osgb"] = y_coords.astype("float32")
         pv["pv_system_row_number"] = pv_system_row_number
 
         # pad out so that there are always n_pv_systems_per_example, pad with zeros
         pad_n = self.n_pv_systems_per_example - len(pv.id)
         pv = pv.pad(id=(0, pad_n), power_mw=((0, 0), (0, pad_n)), constant_values=0)
 
+        # format id
+        pv.__setitem__("id", pv.id.astype("int32"))
+
         return pv
 
     def get_locations(self, t0_datetimes_utc: pd.DatetimeIndex) -> List[SpaceTimeLocation]:

nowcasting_dataset/dataset/xr_utils.py

@@ -17,7 +17,12 @@ def join_list_dataset_to_batch_dataset(datasets: list[xr.Dataset]) -> xr.Dataset
         new_dataset = dataset.expand_dims(dim="example").assign_coords(example=("example", [i]))
         new_datasets.append(new_dataset)
 
-    return xr.concat(new_datasets, dim="example")
+    joined_dataset = xr.concat(new_datasets, dim="example")
+
+    # format example index
+    joined_dataset.__setitem__("example", joined_dataset.example.astype("int32"))
+
+    return joined_dataset
 
 
 def convert_coordinates_to_indexes_for_list_datasets(
@@ -43,7 +48,7 @@ def convert_coordinates_to_indexes(dataset: xr.Dataset) -> xr.Dataset:
 
     for original_dim_name in original_dim_names:
         original_coords = dataset[original_dim_name]
-        new_index_coords = np.arange(len(original_coords))
+        new_index_coords = np.arange(len(original_coords)).astype("int32")
         new_index_dim_name = f"{original_dim_name}_index"
         dataset[original_dim_name] = new_index_coords
         dataset = dataset.rename({original_dim_name: new_index_dim_name})

tests/data_sources/pv/test_pv_data_source.py

@@ -71,6 +71,12 @@ def test_get_example_and_batch():  # noqa: D103
     # start at 6, to avoid some nans
     batch = pv_data_source.get_batch(locations=locations[6:16])
     assert batch.power_mw.shape == (10, 19, DEFAULT_N_PV_SYSTEMS_PER_EXAMPLE)
+    assert str(batch.x_osgb.dtype) == "float32"
+    assert str(batch.y_osgb.dtype) == "float32"
+    assert str(batch.id.dtype) == "int32"
+    assert str(batch.example.dtype) == "int32"
+    assert str(batch.id_index.dtype) == "int32"
+    assert str(batch.time_index.dtype) == "int32"
 
 
 def test_drop_pv_systems_which_produce_overnight():  # noqa: D103