.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "auto_examples/06_manipulating_images/plot_negate_image.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

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

        :ref:`Go to the end <sphx_glr_download_auto_examples_06_manipulating_images_plot_negate_image.py>`
        to download the full example code or to run this example in your browser via Binder

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

.. _sphx_glr_auto_examples_06_manipulating_images_plot_negate_image.py:


Negating an image with math_img
===============================

The goal of this example is to illustrate the use of the function
:func:`nilearn.image.math_img` on T-maps.
We compute a negative image by multiplying its voxel values with -1.

.. GENERATED FROM PYTHON SOURCE LINES 11-13

.. code-block:: Python

    from nilearn import datasets, image, plotting








.. GENERATED FROM PYTHON SOURCE LINES 14-15

Retrieve the data: a motor :term:`contrast` map.

.. GENERATED FROM PYTHON SOURCE LINES 15-18

.. code-block:: Python


    stat_img = datasets.load_sample_motor_activation_image()








.. GENERATED FROM PYTHON SOURCE LINES 19-20

Multiply voxel values by -1.

.. GENERATED FROM PYTHON SOURCE LINES 20-33

.. code-block:: Python

    negative_stat_img = image.math_img("-img", img=stat_img)

    plotting.plot_stat_map(
        stat_img, cut_coords=(36, -27, 66), threshold=3, title="t-map", vmax=9
    )
    plotting.plot_stat_map(
        negative_stat_img,
        cut_coords=(36, -27, 66),
        threshold=3,
        title="Negative t-map",
        vmax=9,
    )
    plotting.show()



.. rst-class:: sphx-glr-horizontal


    *

      .. image-sg:: /auto_examples/06_manipulating_images/images/sphx_glr_plot_negate_image_001.png
         :alt: plot negate image
         :srcset: /auto_examples/06_manipulating_images/images/sphx_glr_plot_negate_image_001.png
         :class: sphx-glr-multi-img

    *

      .. image-sg:: /auto_examples/06_manipulating_images/images/sphx_glr_plot_negate_image_002.png
         :alt: plot negate image
         :srcset: /auto_examples/06_manipulating_images/images/sphx_glr_plot_negate_image_002.png
         :class: sphx-glr-multi-img






.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 14.285 seconds)

**Estimated memory usage:**  160 MB


.. _sphx_glr_download_auto_examples_06_manipulating_images_plot_negate_image.py:

.. only:: html

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

    .. container:: binder-badge

      .. image:: images/binder_badge_logo.svg
        :target: https://mybinder.org/v2/gh/nilearn/nilearn/main?urlpath=lab/tree/notebooks/auto_examples/06_manipulating_images/plot_negate_image.ipynb
        :alt: Launch binder
        :width: 150 px

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

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

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

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


.. only:: html

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

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