.. _sphx_glr_auto_examples_plot_bow.py:


============
Bag of Words
============

This example shows how you can transform a quantized time series (i.e. a time
series represented as a sequence of letters) into a bag of words using
:class:`pyts.bow.BOW`.





.. rst-class:: sphx-glr-script-out

 Out::

    Original time series:
    ['a' 'd' 'a' 'c' 'a' 'b' 'd' 'b' 'd' 'b' 'c' 'b' 'a' 'a' 'd' 'd' 'c' 'c'
     'a' 'a' 'c' 'b' 'b' 'd' 'a' 'a' 'd' 'a' 'a' 'd']


    Bag of words without numerosity reduction:
    {a, d, a, c, a, b, d, b, d, b, c, b, a, a, d, d, c, c, a, a, c, b, b, d, a, a, d, a, a, d}


    Bag of words with numerosity reduction:
    {a, d, a, c, a, b, d, b, d, b, c, b, a, d, c, a, c, b, d, a, d, a, d}




|


.. code-block:: python


    import numpy as np
    from pyts.bow import BOW

    # Parameters
    n_samples = 100
    n_features = 30
    n_bins = 4
    window_size = 1
    alphabet = np.array([chr(i) for i in range(97, 97 + n_bins)])

    # Toy dataset
    rng = np.random.RandomState(41)
    X = alphabet[rng.randint(n_bins, size=(n_samples, n_features))]

    # Bag-of-words transformation
    bow = BOW(window_size, numerosity_reduction=False)
    X_bow = bow.fit_transform(X)
    bow_num = BOW(window_size, numerosity_reduction=True)
    X_bow_num = bow_num.fit_transform(X)

    print("Original time series:")
    print(X[0])
    print("\n")
    print("Bag of words without numerosity reduction:")
    print(''.join(["{", X_bow[0].replace(" ", ", "), "}"]))
    print("\n")
    print("Bag of words with numerosity reduction:")
    print(''.join(["{", X_bow_num[0].replace(" ", ", "), "}"]))

**Total running time of the script:** ( 0 minutes  0.061 seconds)



.. only :: html

 .. container:: sphx-glr-footer


  .. container:: sphx-glr-download

     :download:`Download Python source code: plot_bow.py <plot_bow.py>`



  .. container:: sphx-glr-download

     :download:`Download Jupyter notebook: plot_bow.ipynb <plot_bow.ipynb>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.readthedocs.io>`_