Add Field.time_interval attribute and update time dim in example datasets

Author: VeckoTheGecko

parcels/_datasets/structured/generic.py

@@ -6,7 +6,7 @@
 __all__ = ["N", "T", "datasets"]
 
 N = 30
-T = 10
+T = 13
 
 
 def _rotated_curvilinear_grid():
@@ -45,7 +45,7 @@ def _rotated_curvilinear_grid():
                 {"axis": "Z"},
             ),
             "depth": (["ZG"], np.arange(3 * N), {"axis": "Z"}),
-            "time": (["time"], np.arange(T), {"axis": "T"}),
+            "time": (["time"], xr.date_range("2000", "2001", T), {"axis": "T"}),
             "lon": (
                 ["YG", "XG"],
                 LON,
@@ -120,7 +120,7 @@ def _unrolled_cone_curvilinear_grid():
                 {"axis": "Z"},
             ),
             "depth": (["ZG"], np.arange(3 * N), {"axis": "Z"}),
-            "time": (["time"], np.arange(T), {"axis": "T"}),
+            "time": (["time"], xr.date_range("2000", "2001", T), {"axis": "T"}),
             "lon": (
                 ["YG", "XG"],
                 LON,
@@ -176,7 +176,7 @@ def _unrolled_cone_curvilinear_grid():
             "lon": (["XG"], 2 * np.pi / N * np.arange(0, N)),
             "lat": (["YG"], 2 * np.pi / (2 * N) * np.arange(0, 2 * N)),
             "depth": (["ZG"], np.arange(3 * N)),
-            "time": (["time"], np.arange(T), {"axis": "T"}),
+            "time": (["time"], xr.date_range("2000", "2001", T), {"axis": "T"}),
         },
     ),
     "2d_left_unrolled_cone": _unrolled_cone_curvilinear_grid(),

parcels/field.py

@@ -1,15 +1,17 @@
+from __future__ import annotations
+
 import inspect
 import warnings
 from collections.abc import Callable
 from datetime import datetime
 from enum import IntEnum
-from typing import TYPE_CHECKING
 
 import numpy as np
 import uxarray as ux
 import xarray as xr
 from uxarray.grid.neighbors import _barycentric_coordinates
 
+from parcels._core.utils.time import TimeInterval
 from parcels._core.utils.unstructured import get_vertical_location_from_dims
 from parcels._reprs import default_repr, field_repr
 from parcels._typing import (
@@ -33,9 +35,6 @@
 
 from ._index_search import _search_indices_rectilinear, _search_time_index
 
-if TYPE_CHECKING:
-    pass
-
 __all__ = ["Field", "GridType", "VectorField"]
 
 
@@ -167,6 +166,7 @@ def __init__(
         self.name = name
         self.data = data
         self.grid = grid
+        self.time_interval = get_time_interval(data)
 
         # For compatibility with parts of the codebase that rely on v3 definition of Grid.
         # Should be worked to be removed in v4
@@ -663,3 +663,10 @@ def _assert_compatible_combination(data: xr.DataArray | ux.UxDataArray, grid: ux
             raise ValueError(
                 f"Incompatible data-grid combination. Data is a xarray.DataArray, expected `grid` to be a parcels Grid object, got {type(grid)}."
             )
+
+
+def get_time_interval(data: xr.DataArray | ux.UxDataArray) -> TimeInterval | None:
+    if "time" not in data.dims:
+        return None
+
+    return TimeInterval(data.time.values[0], data.time.values[-1])

tests/v4/test_field.py

@@ -1,3 +1,4 @@
+import numpy as np
 import pytest
 import uxarray as ux
 import xarray as xr
@@ -69,6 +70,21 @@ def test_field_structured_grid_creation(data, grid):
     assert field.grid == grid
 
 
+@pytest.mark.parametrize(
+    "data,grid",
+    [
+        pytest.param(
+            structured_datasets["ds_2d_left"]["data_g"], Grid(structured_datasets["ds_2d_left"]), id="ds_2d_left"
+        ),
+    ],
+)
+def test_field_time_interval(data, grid):
+    """Test creating a field."""
+    field = Field(name="test_field", data=data, grid=grid, mesh_type="flat")
+    assert field.time_interval.left == np.datetime64("2000-01-01")
+    assert field.time_interval.right == np.datetime64("2001-01-01")
+
+
 def test_field_unstructured_grid_creation(): ...
 
 
@@ -79,6 +95,3 @@ def test_field_interpolation_out_of_spatial_bounds(): ...
 
 
 def test_field_interpolation_out_of_time_bounds(): ...
-
-
-def test_field_allow_time_extrapolation(): ...