.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "python/examples/feature_weights.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_python_examples_feature_weights.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_python_examples_feature_weights.py:


Demo for using feature weight to change column sampling
=======================================================

    .. versionadded:: 1.3.0

.. GENERATED FROM PYTHON SOURCE LINES 7-60

.. code-block:: Python


    import argparse

    import numpy as np
    from matplotlib import pyplot as plt

    import xgboost


    def main(args: argparse.Namespace) -> None:
        rng = np.random.RandomState(1994)

        kRows = 4196
        kCols = 10

        X = rng.randn(kRows, kCols)
        y = rng.randn(kRows)
        fw = np.ones(shape=(kCols,))
        for i in range(kCols):
            fw[i] *= float(i)

        dtrain = xgboost.DMatrix(X, y)
        dtrain.set_info(feature_weights=fw)

        # Perform column sampling for each node split evaluation, the sampling process is
        # weighted by feature weights.
        bst = xgboost.train(
            {"tree_method": "hist", "colsample_bynode": 0.2},
            dtrain,
            num_boost_round=10,
            evals=[(dtrain, "d")],
        )
        feature_map = bst.get_fscore()

        # feature zero has 0 weight
        assert feature_map.get("f0", None) is None
        assert max(feature_map.values()) == feature_map.get("f9")

        if args.plot:
            xgboost.plot_importance(bst)
            plt.show()


    if __name__ == "__main__":
        parser = argparse.ArgumentParser()
        parser.add_argument(
            "--plot",
            type=int,
            default=1,
            help="Set to 0 to disable plotting the evaluation history.",
        )
        args = parser.parse_args()
        main(args)


.. _sphx_glr_download_python_examples_feature_weights.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

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

    .. container:: sphx-glr-download sphx-glr-download-python

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

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: feature_weights.zip <feature_weights.zip>`


.. only:: html

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

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