dataset.py 文件源码

def reshape_frames(dataframe, frame_length=12):
    """
    Returns a new dataframe with the given frame length.
    :param dataframe: A pandas DataFrame with one window per row.
    :param frame_length: The desired number of windows for each feature frame. Must divide the number of windows in
                         *dataframe* evenly.
    :return: A new pandas DataFrame with the desired window frame width. The columns of the new data-frame will be
             multi-index so that
        future concatenation of data frames align properly.
    """

    # Assert that the length of the data frame is divisible by
    # frame_length
    n_windows, window_width = dataframe.shape

    if n_windows % frame_length != 0:
        raise ValueError("The dataframe has {} windows which"
                         " is not divisible by the frame"
                         " length {}".format(n_windows, frame_length))
    values = dataframe.values
    n_frames = n_windows / frame_length
    frame_width = window_width * frame_length
    window_columns = dataframe.columns
    column_index = pd.MultiIndex.from_product([range(frame_length),
                                               window_columns],
                                              names=['window', 'feature'])
    reshaped_frame = pd.DataFrame(data=values.reshape(n_frames,
                                                      frame_width),
                                  columns=column_index)
    reshaped_frame.sortlevel(axis=1)
    return reshaped_frame