Source code for pycif.plugins.domains.flexpart.read_domain

import numpy as np




def read_grid(domain, **kwargs):
    """Read the FLEXPART domain from coordinate text files.

    .. note::
        This function is not currently used in practice: ``read_grid``
        always raises ``AttributeError`` (``ficlon``/``ficlat`` are not
        defined in ``input_arguments``), so ``create_domain`` is called
        as the fallback.

    Loads 1-D longitude and latitude arrays from ``domain.ficlon`` /
    ``domain.ficlat``, derives half-step corners, and builds 2-D meshgrids.

    Sets on *domain*: ``nlon``, ``nlat``, ``zlon``, ``zlat``, ``zlonc``,
    ``zlatc``.

    Args:
        domain: FLEXPART domain plugin instance.
        **kwargs: unused.
    """

    zlon = np.loadtxt(domain.ficlon)
    zlat = np.loadtxt(domain.ficlat)

    nlon = zlon.size
    nlat = zlat.size
    
    # Corner coordinates
    dlon = np.ptp(zlon) / (nlon - 1) / 2.
    zlonc = zlon - dlon
    zlonc = np.append(zlonc, zlonc[-1] + 2 * dlon)
    
    dlat = np.ptp(zlat) / (nlat - 1) / 2.
    zlatc = zlat - dlat
    zlatc = np.append(zlatc, zlatc[-1] + 2 * dlat)
    
    # Meshgrids
    zlon, zlat = np.meshgrid(zlon, zlat)
    zlonc, zlatc = np.meshgrid(zlonc, zlatc)
    
    # Saving information to domain attributes
    domain.nlon = nlon
    domain.nlat = nlat
    domain.zlon = zlon
    domain.zlat = zlat
    domain.zlonc = zlonc
    domain.zlatc = zlatc