experimental "timeseries" filter. Syntax is bad, and will change

Author: floriankrb

src/anemoi/transform/filters/sum.py

@@ -8,9 +8,13 @@
 # nor does it submit to any jurisdiction.
 
 
+import logging
+
 from . import filter_registry
 from .base import SimpleFilter
 
+LOG = logging.getLogger(__name__)
+
 
 @filter_registry.register("sum")
 class Sum(SimpleFilter):
@@ -25,6 +29,7 @@ def __init__(
         assert len(formula) == 1
         self.name = list(formula.keys())[0]
         self.args = list(formula.values())[0]
+        LOG.warning("Using the sum filter will be deprecated in the future. Please do not rely on it.")
 
     def forward(self, data):
         return self._transform(data, self.forward_transform, *self.args)

src/anemoi/transform/filters/timeseries.py

@@ -0,0 +1,65 @@
+# (C) Copyright 2024 Anemoi contributors.
+#
+# This software is licensed under the terms of the Apache Licence Version 2.0
+# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# In applying this licence, ECMWF does not waive the privileges and immunities
+# granted to it by virtue of its status as an intergovernmental organisation
+# nor does it submit to any jurisdiction.
+
+
+import logging
+
+import numpy as np
+
+from . import filter_registry
+from .base import SimpleFilter
+
+LOG = logging.getLogger(__name__)
+
+# class MyFilter(SuperSimpleFilter):
+#    def __init__(self, *, param):
+#        self.param = param
+#
+#    def transform(date, tp, lsm):
+#        new = tp + lsm + self.data(self.param, date)
+#        return dict(q_500 = new)
+
+
+@filter_registry.register("timeseries")
+class Timeseries(SimpleFilter):
+    """A source to add a timeseries depending on time but not on location"""
+
+    def __init__(self, *, netcdf=None, template_param="2t"):
+        if netcdf:
+            import xarray as xr
+
+            self.ds = xr.open_dataset(netcdf["path"])  # .to_dataframe()
+        LOG.warning("Using the timeseries filter will be deprecated in the future. Please do not rely on it.")
+
+        self.template_param = template_param
+
+    def forward(self, data):
+        return self._transform(
+            data,
+            self.forward_transform,
+            self.template_param,
+        )
+
+    def forward_transform(self, template):
+        """Convert snow depth and snow density to snow cover"""
+        dt = template.metadata("valid_datetime")
+        template_array = template.to_numpy()
+
+        sel = self.ds.sel(time=dt)
+
+        for name in self.ds.data_vars:
+            value = sel[name].values
+            data = np.full_like(template_array, value)
+            yield self.new_field_from_numpy(data, template=template, param=name)
+
+    def backward(self, data):
+        raise NotImplementedError("SnowCover is not reversible")
+
+    def backward_transform(self, sd, rsn):
+        raise NotImplementedError("SnowCover is not reversible")