def METHOD_NAME(time_value_pair):
    '''
    converts a numpy array containing basic_types.time_value_pair to a
    numpy array containing basic_types.datetime_value_1d. It simply drops the
    2nd component of value: eg:
      time_value_pair[0] = ((datetime), (val_0, val_1))
    becomes: output = ((datetime), (val_0,))
    This is partly used for timeseries for Tide data and in this case, the
    v-component of velocity (u, v) is 0.0
    This function does not perform a check to see if 2nd component is 0.0, it
    simply drops it.
    :param time_value_pair: numpy array of type basic_types.time_value_pair
    '''
    if time_value_pair.dtype != basic_types.time_value_pair:
        raise ValueError('Method expects a numpy array containing '
                         'basic_types.time_value_pair')
    datetime_value_1d = np.zeros((len(time_value_pair), ),
                                 dtype=basic_types.datetime_value_1d)
    datetime_value_1d['time'] = time_utils.sec_to_date(time_value_pair['time'])
    datetime_value_1d['value'][:] = time_value_pair['value']['u']
    return datetime_value_1d