@classmethod
def export_to_hdf5(cls, h5_file, model, nids):
    """exports the nodes in a vectorized way"""
    comments = []
    cp = []
    xyz = []
    cd = []
    ps = []
    seid = []
    for nid in nids:
        node = model.nodes[nid]
        xyz.append(node.xyz)
        cp.append(node.cp)
        cd.append(node.cd)
        psi = 0 if node.ps == '' else int(node.ps)
        ps.append(psi)
        seid.append(node.seid)
    h5_file.create_dataset('nid', data=nids)
    h5_file.create_dataset('xyz', data=xyz)
    h5_file.create_dataset('cp', data=cp)
    h5_file.create_dataset('cd', data=cd)
    h5_file.create_dataset('ps', data=ps)
    h5_file.create_dataset('seid', data=seid)
