Define .dims property. FutureWarning on .dimensions. Fixes #217

docs/api.rst

@@ -190,7 +190,8 @@ UGRID1D Topology
     Ugrid1d
 
     Ugrid1d.topology_dimension
-    Ugrid1d.dimensions
+    Ugrid1d.dims
+    Ugrid1d.sizes
     Ugrid1d.attrs
 
     Ugrid1d.n_node
@@ -249,7 +250,8 @@ UGRID2D Topology
     Ugrid2d
 
     Ugrid2d.topology_dimension
-    Ugrid2d.dimensions
+    Ugrid2d.dims
+    Ugrid2d.sizes
     Ugrid2d.attrs
 
     Ugrid2d.n_node

tests/test_partitioning.py

@@ -41,7 +41,7 @@ def test_labels_to_indices():
 
 def test_single_ugrid_chunk():
     grid = generate_mesh_2d(3, 3)
-    ugrid_dims = set(grid.dimensions)
+    ugrid_dims = set(grid.dims)
     da = xr.DataArray(np.ones(grid.n_face), dims=(grid.face_dimension,))
     assert pt.single_ugrid_chunk(da, ugrid_dims) is da
 

tests/test_ugrid1d.py

@@ -268,10 +268,13 @@ def test_dimensions():
     grid = grid1d()
     assert grid.node_dimension == f"{NAME}_nNodes"
     assert grid.edge_dimension == f"{NAME}_nEdges"
-    assert grid.dimensions == {
+    assert grid.dims == (f"{NAME}_nNodes", f"{NAME}_nEdges")
+    assert grid.sizes == {
         f"{NAME}_nNodes": 3,
         f"{NAME}_nEdges": 2,
     }
+    with pytest.warns(FutureWarning):
+        assert grid.dimensions == grid.sizes
 
 
 @requires_meshkernel

tests/test_ugrid2d.py

@@ -444,11 +444,18 @@ def test_dimensions():
     assert grid.node_dimension == f"{NAME}_nNodes"
     assert grid.edge_dimension == f"{NAME}_nEdges"
     assert grid.face_dimension == f"{NAME}_nFaces"
-    assert grid.dimensions == {
+    assert grid.dims == (
+        f"{NAME}_nNodes",
+        f"{NAME}_nEdges",
+        f"{NAME}_nFaces",
+    )
+    assert grid.sizes == {
         f"{NAME}_nNodes": 7,
         f"{NAME}_nEdges": 10,
         f"{NAME}_nFaces": 4,
     }
+    with pytest.warns(FutureWarning):
+        assert grid.dimensions == grid.sizes
 
 
 def test_edge_node_connectivity():

xugrid/core/wrap.py

@@ -32,9 +32,9 @@ def maybe_xugrid(obj, topology, old_indexes=None):
 
     # Topology can either be a sequence of grids or a grid.
     if isinstance(topology, (list, set, tuple)):
-        grids = {dim: grid for grid in topology for dim in grid.dimensions}
+        grids = {dim: grid for grid in topology for dim in grid.dims}
     else:
-        grids = {dim: topology for dim in topology.dimensions}
+        grids = {dim: topology for dim in topology.dims}
 
     item_grids = unique_grids([grids[dim] for dim in obj.dims if dim in grids])
 
@@ -183,7 +183,7 @@ class DatasetForwardMixin:
 
 
 def assign_ugrid_coords(obj, grids):
-    grid_dims = ChainMap(*(grid.dimensions for grid in grids))
+    grid_dims = ChainMap(*(grid.sizes for grid in grids))
     ugrid_dims = set(grid_dims.keys()).intersection(obj.dims)
     ugrid_coords = {dim: RangeIndex(0, grid_dims[dim]) for dim in ugrid_dims}
     obj = obj.assign_coords(ugrid_coords)
@@ -385,16 +385,12 @@ def __setitem__(self, key, value):
             # Check if the dimensions occur in self.
             # if they don't, the grid should be added.
             if self.grids is not None:
-                alldims = set(
-                    chain.from_iterable([grid.dimensions for grid in self.grids])
-                )
-                matching_dims = set(value.grid.dimensions).intersection(alldims)
+                alldims = set(chain.from_iterable([grid.dims for grid in self.grids]))
+                matching_dims = set(value.grid.dims).intersection(alldims)
                 if matching_dims:
                     append = False
                     # If they do match: the grids should match.
-                    grids = {
-                        dim: grid for grid in self.grids for dim in grid.dimensions
-                    }
+                    grids = {dim: grid for grid in self.grids for dim in grid.dims}
                     firstdim = next(iter(matching_dims))
                     grid_to_check = grids[firstdim]
                     if not grid_to_check.equals(value.grid):

xugrid/plot/plot.py

@@ -625,11 +625,11 @@ def __init__(self, obj):
         darray = obj.obj
         grid = obj.grid
 
-        invalid = set(darray.dims) - set(grid.dimensions)
+        invalid = set(darray.dims) - set(grid.dims)
         if invalid:
             raise ValueError(
                 f"UgridDataArray contains non-topology dimensions: {invalid}.\n"
-                f"Expected only one of {set(grid.dimensions.keys())}."
+                f"Expected only one of {grid.dims}."
             )
 
         self.grid = grid

xugrid/ugrid/partitioning.py

@@ -156,7 +156,7 @@ def validate_partition_topology(grouped: defaultdict[str, UgridType]) -> None:
                 f"same type, received: {types}"
             )
 
-        griddims = list({tuple(grid.dimensions) for grid in grids})
+        griddims = list({grid.dims for grid in grids})
         if len(griddims) > 1:
             raise ValueError(
                 f"Dimension names on UGRID topology {name} do not match "
@@ -365,7 +365,7 @@ def merge_partitions(partitions, merge_ugrid_chunks: bool = True):
 
     # Collect grids
     grids = [grid for p in partitions for grid in p.grids]
-    ugrid_dims = {dim for grid in grids for dim in grid.dimensions}
+    ugrid_dims = {dim for grid in grids for dim in grid.dims}
     grids_by_name = group_grids_by_name(partitions)
 
     data_objects_by_name = group_data_objects_by_gridname(partitions)

xugrid/ugrid/ugrid1d.py

@@ -262,7 +262,12 @@ def core_dimension(self):
         return self.node_dimension
 
     @property
-    def dimensions(self):
+    def dims(self):
+        # Tuple to preserve order, unlike set.
+        return (self.node_dimension, self.edge_dimension)
+
+    @property
+    def sizes(self):
         return {self.node_dimension: self.n_node, self.edge_dimension: self.n_edge}
 
     def connectivity_matrix(self, dim: str, xy_weights: bool):
@@ -432,17 +437,15 @@ def isel(self, indexers=None, return_index=False, **indexers_kwargs):
             their respective index. Only returned if return_index is True.
         """
         indexers = either_dict_or_kwargs(indexers, indexers_kwargs, "isel")
-        alldims = set(self.dimensions)
+        alldims = self.dims
         invalid = indexers.keys() - alldims
         if invalid:
             raise ValueError(
                 f"Dimensions {invalid} do not exist. Expected one of {alldims}"
             )
 
-        indexers = {
-            k: as_pandas_index(v, self.dimensions[k]) for k, v in indexers.items()
-        }
-        nodedim, edgedim = self.dimensions
+        indexers = {k: as_pandas_index(v, self.sizes[k]) for k, v in indexers.items()}
+        nodedim, edgedim = self.dims
         edge_index = {}
         if nodedim in indexers:
             node_index = indexers[nodedim]

xugrid/ugrid/ugrid2d.py

@@ -414,7 +414,16 @@ def core_dimension(self):
         return self.face_dimension
 
     @property
-    def dimensions(self):
+    def dims(self):
+        # Tuple to preserve order, unlike set.
+        return (
+            self.node_dimension,
+            self.edge_dimension,
+            self.face_dimension,
+        )
+
+    @property
+    def sizes(self):
         return {
             self.node_dimension: self.n_node,
             self.edge_dimension: self.n_edge,
@@ -1160,17 +1169,15 @@ def isel(self, indexers=None, return_index=False, **indexers_kwargs):
             True.
         """
         indexers = either_dict_or_kwargs(indexers, indexers_kwargs, "isel")
-        alldims = set(self.dimensions)
+        alldims = set(self.dims)
         invalid = indexers.keys() - alldims
         if invalid:
             raise ValueError(
                 f"Dimensions {invalid} do not exist. Expected one of {alldims}"
             )
 
-        indexers = {
-            k: as_pandas_index(v, self.dimensions[k]) for k, v in indexers.items()
-        }
-        nodedim, edgedim, facedim = self.dimensions
+        indexers = {k: as_pandas_index(v, self.sizes[k]) for k, v in indexers.items()}
+        nodedim, edgedim, facedim = self.dims
         face_index = {}
         if nodedim in indexers:
             node_index = indexers[nodedim]

xugrid/ugrid/ugridbase.py

@@ -1,7 +1,8 @@
 import abc
 import copy
+import warnings
 from itertools import chain
-from typing import Tuple, Type, Union, cast
+from typing import Dict, Tuple, Type, Union, cast
 
 import numpy as np
 import pandas as pd
@@ -60,9 +61,9 @@ def align(obj, grids, old_indexes):
     if old_indexes is None:
         return obj, grids
 
-    ugrid_dims = set(
-        chain.from_iterable(grid.dimensions for grid in grids)
-    ).intersection(old_indexes)
+    ugrid_dims = set(chain.from_iterable(grid.dims for grid in grids)).intersection(
+        old_indexes
+    )
     new_indexes = {
         k: index
         for k, index in obj.indexes.items()
@@ -74,7 +75,7 @@ def align(obj, grids, old_indexes):
     # Group the indexers by grid
     new_grids = []
     for grid in grids:
-        ugrid_dims = set(grid.dimensions).intersection(new_indexes)
+        ugrid_dims = set(grid.dims).intersection(new_indexes)
         ugrid_indexes = {dim: new_indexes[dim] for dim in ugrid_dims}
         newgrid, indexers = grid.isel(indexers=ugrid_indexes, return_index=True)
         indexers = {
@@ -98,7 +99,29 @@ def core_dimension(self):
 
     @property
     @abc.abstractmethod
-    def dimensions(self):
+    def dims(self) -> Tuple[str]:
+        pass
+
+    @property
+    def dimensions(self) -> Dict[str, Dict[str, str]]:
+        """
+        Mapping from UGRID dimension names to lengths.
+
+        This property will be changed to return a type more consistent with
+        DataArray.dims in the future, i.e. a set of dimension names.
+        """
+
+        warnings.warn(
+            ".dimensions will is replaced by .dims and its return type is a set "
+            "of dimension names in future. To access a mapping of names to "
+            "lengths, use .sizes instead.",
+            FutureWarning,
+        )
+        return self.sizes
+
+    @property
+    @abc.abstractmethod
+    def sizes(self):
         pass
 
     @property
@@ -175,7 +198,7 @@ def _create_data_array(self, data: ArrayLike, dimension: str):
                 f"Data has {data.ndim} dimensions."
             )
         len_data = len(data)
-        len_grid = self.dimensions[dimension]
+        len_grid = self.sizes[dimension]
         if len_data != len_grid:
             raise ValueError(
                 f"Conflicting sizes for dimension {dimension}: length "
@@ -342,10 +365,6 @@ def max_connectivity_dimensions(self) -> tuple[str]:
     def max_connectivity_sizes(self) -> dict[str, int]:
         return {}
 
-    @property
-    def sizes(self) -> dict[str, int]:
-        return self.dimensions
-
     @property
     def node_coordinates(self) -> FloatArray:
         """Coordinates (x, y) of the nodes (vertices)"""