Refactor and unify regridding schemes (#198)

* rearrange helper functions

* tidy dimension variable names

* switch data chunking

* fix tests

* fix tests

* refactor AreaWeightedRegridder

* fix

* fix

* fix keywords

* refactor unstructured schemes

* fix tests

* fill out unstructured schemes

* add error handling

* remove old code, improve docstrings

* refresh cache

* remove old code

* increment pip cache

* remove old code

* fix imports

* fix test imports

* remove imports

* fix imports

* fix imports

* fix imports

* fix test

* remove old code

* add test files

* run benchmarks on python 3.9, add test files

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* refresh cache

* refresh cache

* lint fix

* reset CI changes

* fix tests

* add and fix tests

* fix tests

* revert changes to _mesh_to_MeshInfo

* add tests

* revert lazy data handling to previous solution

* address review comments

* address review comments

* address review comments

* address review comments

* add test, fix docstring

* fix tests

* remove superfluous test__cube_to_GridInfo.py

* move test__mesh_to_MeshInfo.py, fix tests

* move tests

* fix tests

* parameterize laziness tests

* clarify target type

* remove resolution keyword

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* fix loading

* combine docstring descriptions

* remove TODO

* retain more detailed commented code

* retain mesh checking behaviour

* fix benchmarks

* fix tests

* Apply suggestions from code review

Co-authored-by: Martin Yeo <40734014+trexfeathers@users.noreply.github.com>

* address review comments

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Martin Yeo <40734014+trexfeathers@users.noreply.github.com>

benchmarks/benchmarks/esmf_regridder/scalability.py

@@ -275,7 +275,7 @@ def src_cube(self, height):
 
     def add_src_metadata(self, cube):
         """Add appropriate MeshCoords from _gridlike_mesh to the given `cube`."""
-        from esmf_regrid.tests.unit.experimental.unstructured_scheme.test__mesh_to_MeshInfo import (
+        from esmf_regrid.tests.unit.schemes.test__mesh_to_MeshInfo import (
             _gridlike_mesh,
         )
 
@@ -306,7 +306,7 @@ def setup_cache(self):
 
     def tgt_cube(self):
         """Cube containing the regridding target grid."""
-        from esmf_regrid.tests.unit.experimental.unstructured_scheme.test__mesh_to_MeshInfo import (
+        from esmf_regrid.tests.unit.schemes.test__mesh_to_MeshInfo import (
             _gridlike_mesh,
         )
 

benchmarks/benchmarks/generate_data.py

@@ -227,7 +227,7 @@ def external(*args, **kwargs):
         """
         from iris import save
 
-        from esmf_regrid.tests.unit.experimental.unstructured_scheme.test__mesh_to_MeshInfo import (
+        from esmf_regrid.tests.unit.schemes.test__mesh_to_MeshInfo import (
             _gridlike_mesh_cube as original,
         )
 

esmf_regrid/experimental/io.py

@@ -228,15 +228,23 @@ def load_regridder(filename):
     else:
         use_tgt_mask = False
 
+    if scheme is GridToMeshESMFRegridder:
+        resolution_keyword = "src_resolution"
+    elif scheme is MeshToGridESMFRegridder:
+        resolution_keyword = "tgt_resolution"
+    else:
+        raise NotImplementedError
+    kwargs = {resolution_keyword: resolution}
+
     regridder = scheme(
         src_cube,
         tgt_cube,
         mdtol=mdtol,
         method=method,
         precomputed_weights=weight_matrix,
-        resolution=resolution,
         use_src_mask=use_src_mask,
         use_tgt_mask=use_tgt_mask,
+        **kwargs,
     )
 
     esmf_version = weights_cube.attributes[VERSION_ESMF]