Add site backtest script (#192)

Add site PVNet backtest functionality

README.md

@@ -343,6 +343,11 @@ val data batches, you can now train PVNet by running:
 python run.py
 ```
 
+## Backtest
+
+If you have succesfully trained a PVNet model and have a saved model checkpoint you can create a backtest using this, e.g. forecasts on historical data to evaluate forecast accuracy/skill. This can be done by running one of the scripts in this repo such as [the UK gsp backtest script](scripts/backtest_uk_gsp.py) or the [the pv site backtest script](scripts/backtest_sites.py), further info on how to run these are in each backtest file.
+
+
 ## Testing
 
 You can use `python -m pytest tests` to run tests

pvnet/data/pv_site_datamodule.py

@@ -34,7 +34,7 @@ def _get_datapipe(self, start_time, end_time):
     def _get_premade_batches_datapipe(self, subdir, shuffle=False):
         filenames = list(glob.glob(f"{self.batch_dir}/{subdir}/*.nc"))
         data_pipeline = pvnet_site_netcdf_datapipe(
-            keys=["pv", "nwp"],
+            keys=["pv", "nwp"],  # add other keys e.g. sat if used as input in site model
             filenames=filenames,
         )
         data_pipeline = (

pvnet/utils.py

@@ -69,6 +69,34 @@ def __call__(self, gsp_id: int) -> Location:
         )
 
 
+class SiteLocationLookup:
+    """Query object for site location from site ID"""
+
+    def __init__(self, long: xr.DataArray, lat: xr.DataArray):
+        """Query object for site location from site ID
+
+        Args:
+            long: DataArray of the longitude coordinates for any given site ID
+            lat: DataArray of the latitude coordinates for any given site ID
+
+        """
+        self.longitude = long
+        self.latitude = lat
+
+    def __call__(self, site_id: int) -> Location:
+        """Returns the locations for the input site IDs.
+
+        Args:
+            site_id: Integer ID of the site
+        """
+        return Location(
+            coordinate_system="lon_lat",
+            x=self.longitude.sel(pv_system_id=site_id).item(),
+            y=self.latitude.sel(pv_system_id=site_id).item(),
+            id=site_id,
+        )
+
+
 def extras(config: DictConfig) -> None:
     """A couple of optional utilities.