fix loose ends and make all relevant tests succeed

Author: mats-knmi

pysteps/decorators.py

@@ -9,7 +9,6 @@
 .. autosummary::
     :toctree: ../generated/
 
-    postprocess_import
     check_input_frames
     prepare_interpolator
     memoize
@@ -22,8 +21,6 @@
 
 import numpy as np
 
-from pysteps.xarray_helpers import convert_input_to_xarray_dataset
-
 
 def _add_extra_kwrds_to_docstrings(target_func, extra_kwargs_doc_text):
     """
@@ -44,76 +41,6 @@ def _add_extra_kwrds_to_docstrings(target_func, extra_kwargs_doc_text):
     return target_func
 
 
-def postprocess_import(fillna=np.nan, dtype="double"):
-    """
-    Postprocess the imported precipitation data.
-    Operations:
-    - Allow type casting (dtype keyword)
-    - Set invalid or missing data to predefined value (fillna keyword)
-    This decorator replaces the text "{extra_kwargs}" in the function's
-    docstring with the documentation of the keywords used in the postprocessing.
-    The additional docstrings are added as "Other Parameters" in the importer function.
-
-    Parameters
-    ----------
-    dtype: str
-        Default data type for precipitation. Double precision by default.
-    fillna: float or np.nan
-        Default value used to represent the missing data ("No Coverage").
-        By default, np.nan is used.
-        If the importer returns a MaskedArray, all the masked values are set to the
-        fillna value. If a numpy array is returned, all the invalid values (nan and inf)
-        are set to the fillna value.
-
-    """
-
-    def _postprocess_import(importer):
-        @wraps(importer)
-        def _import_with_postprocessing(*args, **kwargs):
-            precip, quality, metadata = importer(*args, **kwargs)
-
-            _dtype = kwargs.get("dtype", dtype)
-
-            accepted_precisions = ["float32", "float64", "single", "double"]
-            if _dtype not in accepted_precisions:
-                raise ValueError(
-                    "The selected precision does not correspond to a valid value."
-                    "The accepted values are: " + str(accepted_precisions)
-                )
-
-            if isinstance(precip, np.ma.MaskedArray):
-                invalid_mask = np.ma.getmaskarray(precip)
-                precip.data[invalid_mask] = fillna
-            else:
-                # If plain numpy arrays are used, the importers should indicate
-                # the invalid values with np.nan.
-                _fillna = kwargs.get("fillna", fillna)
-                if _fillna is not np.nan:
-                    mask = ~np.isfinite(precip)
-                    precip[mask] = _fillna
-
-            return convert_input_to_xarray_dataset(
-                precip.astype(_dtype), quality, metadata
-            )
-
-        extra_kwargs_doc = """
-            Other Parameters
-            ----------------
-            dtype: str
-                Data-type to which the array is cast.
-                Valid values:  "float32", "float64", "single", and "double".
-            fillna: float or np.nan
-                Value used to represent the missing data ("No Coverage").
-                By default, np.nan is used.
-            """
-
-        _add_extra_kwrds_to_docstrings(_import_with_postprocessing, extra_kwargs_doc)
-
-        return _import_with_postprocessing
-
-    return _postprocess_import
-
-
 def check_input_frames(
     minimum_input_frames=2, maximum_input_frames=np.inf, just_ndim=False
 ):

pysteps/extrapolation/eulerian_persistence.py

@@ -1,47 +1,40 @@
 import numpy as np
-import xarray as xr
-from pysteps.xarray_helpers import convert_output_to_xarray_dataset
 
 
-def extrapolate(precip_dataset: xr.Dataset, timesteps, outval=np.nan, **kwargs):
+def extrapolate(precip, velocity, timesteps, outval=np.nan, **kwargs):
     """
     A dummy extrapolation method to apply Eulerian persistence to a
     two-dimensional precipitation field. The method returns the a sequence
     of the same initial field with no extrapolation applied (i.e. Eulerian
     persistence).
-
     Parameters
     ----------
-    precip_dataset : xarray.Dataset
-        xarray dataset containing the input precipitation field. All
+    precip : array-like
+        Array of shape (m,n) containing the input precipitation field. All
         values are required to be finite.
+    velocity : array-like
+        Not used by the method.
     timesteps : int or list of floats
         Number of time steps or a list of time steps.
     outval : float, optional
         Not used by the method.
-
     Other Parameters
     ----------------
     return_displacement : bool
         If True, return the total advection velocity (displacement) between the
         initial input field and the advected one integrated along
         the trajectory. Default : False
-
     Returns
     -------
     out : array or tuple
         If return_displacement=False, return a sequence of the same initial field
         of shape (num_timesteps,m,n). Otherwise, return a tuple containing the
         replicated fields and a (2,m,n) array of zeros.
-
     References
     ----------
     :cite:`GZ2002`
-
     """
-    del outval  # Unused by _eulerian_persistence
-    precip_var = precip_dataset.attrs["precip_var"]
-    precip = precip_dataset[precip_var].values[-1]
+    del velocity, outval  # Unused by _eulerian_persistence
 
     if isinstance(timesteps, int):
         num_timesteps = timesteps
@@ -51,11 +44,8 @@ def extrapolate(precip_dataset: xr.Dataset, timesteps, outval=np.nan, **kwargs):
     return_displacement = kwargs.get("return_displacement", False)
 
     extrapolated_precip = np.repeat(precip[np.newaxis, :, :], num_timesteps, axis=0)
-    extrapolated_precip_dataset = convert_output_to_xarray_dataset(
-        precip_dataset, timesteps, extrapolated_precip
-    )
 
     if not return_displacement:
-        return extrapolated_precip_dataset
+        return extrapolated_precip
     else:
-        return extrapolated_precip_dataset, np.zeros((2,) + extrapolated_precip.shape)
+        return extrapolated_precip, np.zeros((2,) + extrapolated_precip.shape)