def write_fieldtrip(data, filename):
    """Export data to FieldTrip.

    Parameters
    ----------
    data : instance of ChanTime
        data with only one trial
    filename : path to file
        file to export to (include '.mat')

    Notes
    -----
    It saves mat file using Version 6 ('-v7') because it relies on scipy.io
    functions. Therefore it cannot store data larger than 2 GB.
    """
    n_trl = data.number_of('trial')
    trial = empty(n_trl, dtype='O')
    time = empty(n_trl, dtype='O')

    for trl in range(n_trl):
        trial[trl] = data.data[trl]
        time[trl] = data.axis['time'][trl]

    ft_data = {'fsample': float(data.s_freq),
               'label': data.axis['chan'][0].astype('O'),
               'trial': trial,
               'time': time,
               'cfg': 'Converted from wonambi on ' + str(datetime.now()),
               }

    savemat(filename, {VAR: ft_data})
Export data to FieldTrip.

    Parameters
    ----------
    data : instance of ChanTime
        data with only one trial
    filename : path to file
        file to export to (include '.mat')

    Notes
    -----
    It saves mat file using Version 6 ('-v7') because it relies on scipy.io
    functions. Therefore it cannot store data larger than 2 GB.