def get_meshes_fld(step, var):
fld = step.fields[var]<EOL>if step.geom.twod_xz:<EOL><INDENT>xmesh, ymesh = step.geom.x_mesh[:, <NUM_LIT:0>, :], step.geom.z_mesh[:, <NUM_LIT:0>, :]<EOL>fld = fld[:, <NUM_LIT:0>, :, <NUM_LIT:0>]<EOL><DEDENT>elif step.geom.cartesian and step.geom.twod_yz:<EOL><INDENT>xmesh, ymesh = step.geom.y_mesh[<NUM_LIT:0>, :, :], step.geom.z_mesh[<NUM_LIT:0>, :, :]<EOL>fld = fld[<NUM_LIT:0>, :, :, <NUM_LIT:0>]<EOL><DEDENT>else:  <EOL><INDENT>xmesh, ymesh = step.geom.x_mesh[<NUM_LIT:0>, :, :], step.geom.y_mesh[<NUM_LIT:0>, :, :]<EOL>fld = fld[<NUM_LIT:0>, :, :, <NUM_LIT:0>]<EOL><DEDENT>return xmesh, ymesh, fld<EOL>
Return scalar field along with coordinates meshes.

    Only works properly in 2D geometry.

    Args:
        step (:class:`~stagpy.stagyydata._Step`): a step of a StagyyData
            instance.
        var (str): scalar field name.
    Returns:
        tuple of :class:`numpy.array`: xmesh, ymesh, fld
            2D arrays containing respectively the x position, y position, and
            the value of the requested field.