Function test_interpolate_nd

xarray/tests/test_interp.py:304–363

(case: int, method: InterpnOptions, nd_interp_coords)

    ],
)
def test_interpolate_nd(case: int, method: InterpnOptions, nd_interp_coords) -> None:
    da = get_example_data(case)

    # grid -> grid
    xdestnp = nd_interp_coords["xdestnp"]
    ydestnp = nd_interp_coords["ydestnp"]
    zdestnp = nd_interp_coords["zdestnp"]
    grid_grid_points = nd_interp_coords["grid_grid_points"]
    # the presence/absence of z coordinate may affect nd interpolants, even when the
    # coordinate is unchanged
    # TODO: test this?
    actual = da.interp(x=xdestnp, y=ydestnp, z=zdestnp, method=method)
    expected_data = scipy.interpolate.interpn(
        points=(da.x, da.y, da.z),
        values=da.load().data,
        xi=grid_grid_points,
        method=method,
        bounds_error=False,
    ).reshape((len(xdestnp), len(ydestnp), len(zdestnp)))
    expected = xr.DataArray(
        expected_data,
        dims=["x", "y", "z"],
        coords={
            "x": xdestnp,
            "y": ydestnp,
            "z": zdestnp,
            "x2": da["x2"].interp(x=xdestnp, method=method),
        },
    )
    assert_allclose(actual.transpose("x", "y", "z"), expected.transpose("x", "y", "z"))

    # grid -> 1d-sample
    xdest = nd_interp_coords["xdest"]
    ydest = nd_interp_coords["ydest"]
    zdest = nd_interp_coords["zdest"]
    grid_oned_points = nd_interp_coords["grid_oned_points"]
    actual = da.interp(x=xdest, y=ydest, z=zdest, method=method)
    expected_data_1d: np.ndarray = scipy.interpolate.interpn(
        points=(da.x, da.y, da.z),
        values=da.data,
        xi=grid_oned_points,
        method=method,
        bounds_error=False,
    ).reshape([len(xdest), len(zdest)])
    expected = xr.DataArray(
        expected_data_1d,
        dims=["y", "z"],
        coords={
            "y": ydest,
            "z": zdest,
            "x": ("y", xdest.values),
            "x2": da["x2"].interp(x=xdest, method=method),
        },
    )

    assert_allclose(actual.transpose("y", "z"), expected)

    # reversed order