Source code for pycif.plugins.datastreams.fields.lmdz_inicond_ico.read

from __future__ import annotations

import datetime

import numpy as np
import xarray as xr
from .....utils.check.errclass import CifValueError
from .....utils.hdf5 import _hdf5_lock




def read(
    self,
    name: str,
    varnames: str,
    dates: list[tuple[datetime.datetime, datetime.datetime]],
    files: list[str],
    tracer: object | None = None,
    **kwargs,
) -> xr.DataArray:
    """Read a mixing-ratio initial condition (icosahedral grid) into a pyCIF DataArray.

    Args:
        self: The field/tracer Plugin.
        name: Name of the component; used as fallback variable name.
        varnames: Name of the variable to read; if empty, ``name`` is used
            instead.
        dates: List of date entries; only the first date is used as the
            output time coordinate.
        files: List with a single inicond file path.
        tracer: Unused.
        **kwargs: Unused.

    Returns:
        xarray.DataArray: A 4-dimensional ``(time, lev, lat, lon)`` array
        with singleton ``time`` and ``lat`` axes (the icosahedral cell
        dimension is carried by ``lon``).

    Raises:
        CifValueError: If more than one file is given.
    """
    varnames = varnames if varnames else name

    if len(files) > 1:
        raise CifValueError("multiple files provided for initial conditions")
    (path,) = files

    with _hdf5_lock:
        with xr.open_dataset(path) as ds:
            data = ds[varnames].values

    xmod = xr.DataArray(
        data[np.newaxis, :, np.newaxis, :],
        coords={"time": [dates[0][0]]},
        dims=("time", "lev", "lat", "lon"),
    )

    return xmod