.. only:: html

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

        Click :ref:`here <sphx_glr_download_auto_examples_06_manipulating_images_plot_compare_mean_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_compare_mean_image.py:


Comparing the means of 2 images
===============================

The goal of this example is to illustrate the use of the function
:func:`nilearn.image.math_img` with a list of images as input.
We compare the means of 2 resting state 4D images. The mean of the images
could have been computed with nilearn :func:`nilearn.image.mean_img` function.

Fetching 2 subject movie watching brain development fmri datasets.


.. code-block:: default

    from nilearn import datasets
    dataset = datasets.fetch_development_fmri(n_subjects=2)









Print basic information on the adhd subjects resting state datasets.


.. code-block:: default

    print('Subject 1 resting state dataset at: %s' % dataset.func[0])
    print('Subject 2 resting state dataset at: %s' % dataset.func[1])






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

 Out:

 .. code-block:: none

    Subject 1 resting state dataset at: /home/varoquau/nilearn_data/development_fmri/development_fmri/sub-pixar123_task-pixar_space-MNI152NLin2009cAsym_desc-preproc_bold.nii.gz
    Subject 2 resting state dataset at: /home/varoquau/nilearn_data/development_fmri/development_fmri/sub-pixar001_task-pixar_space-MNI152NLin2009cAsym_desc-preproc_bold.nii.gz




Comparing the means of the 2 movie watching datasets.


.. code-block:: default

    from nilearn import plotting, image

    result_img = image.math_img("np.mean(img1, axis=-1) - np.mean(img2, axis=-1)",
                                img1=dataset.func[0],
                                img2=dataset.func[1])

    plotting.plot_stat_map(result_img,
                           title="Comparing means of 2 resting state 4D images.")
    plotting.show()



.. image:: /auto_examples/06_manipulating_images/images/sphx_glr_plot_compare_mean_image_001.png
    :alt: plot compare mean image
    :class: sphx-glr-single-img






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

   **Total running time of the script:** ( 0 minutes  3.671 seconds)


.. _sphx_glr_download_auto_examples_06_manipulating_images_plot_compare_mean_image.py:


.. only :: html

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


  .. container:: binder-badge

    .. image:: https://mybinder.org/badge_logo.svg
      :target: https://mybinder.org/v2/gh/nilearn/nilearn.github.io/master?filepath=examples/auto_examples/06_manipulating_images/plot_compare_mean_image.ipynb
      :width: 150 px


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

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



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

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


.. only:: html

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

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