.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "auto_examples/region_of_interest/fast_fourier_transform_live.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_region_of_interest_fast_fourier_transform_live.py>`
        to download the full example code.

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

.. _sphx_glr_auto_examples_region_of_interest_fast_fourier_transform_live.py:


Live FFT
========

Get interactive fast Fourier transform (FFT) from a subset of a Signal2D
using RectangularROI.

.. GENERATED FROM PYTHON SOURCE LINES 9-13

.. code-block:: Python


    import hyperspy.api as hs
    import numpy as np








.. GENERATED FROM PYTHON SOURCE LINES 14-15

Create a signal:

.. GENERATED FROM PYTHON SOURCE LINES 15-17

.. code-block:: Python

    s = hs.data.atomic_resolution_image()








.. GENERATED FROM PYTHON SOURCE LINES 18-19

Add noise to the signal to make it more realistic

.. GENERATED FROM PYTHON SOURCE LINES 19-22

.. code-block:: Python

    s.data *= 1E3
    s.data += np.random.default_rng().poisson(s.data)








.. GENERATED FROM PYTHON SOURCE LINES 23-24

Create the ROI, here a :py:class:`~.api.roi.RectangularROI`:

.. GENERATED FROM PYTHON SOURCE LINES 24-26

.. code-block:: Python

    roi = hs.roi.RectangularROI()








.. GENERATED FROM PYTHON SOURCE LINES 27-30

Slice signal with the ROI. By using the `interactive` function, the
output signal ``sliced_signal`` will update automatically.
The ROI will be added automatically on the signal plot.

.. GENERATED FROM PYTHON SOURCE LINES 30-36

.. code-block:: Python

    s.plot()
    sliced_signal = roi.interactive(s, recompute_out_event=None)

    # Choose the second figure as gallery thumbnail:
    # sphinx_gallery_thumbnail_number = 2




.. image-sg:: /auto_examples/region_of_interest/images/sphx_glr_fast_fourier_transform_live_001.png
   :alt:  Signal
   :srcset: /auto_examples/region_of_interest/images/sphx_glr_fast_fourier_transform_live_001.png
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 37-41

Get the FFT of this sliced signal, and plot it
Apodization is used to smoothen the edge of the image before taking the FFT
to remove streaks from the FFT - see the :ref:`signal.fft` section of the
user guide for more details:

.. GENERATED FROM PYTHON SOURCE LINES 41-43

.. code-block:: Python

    s_fft = hs.interactive(sliced_signal.fft, apodization=True, shift=True, recompute_out_event=None)
    s_fft.plot(power_spectrum=True)



.. image-sg:: /auto_examples/region_of_interest/images/sphx_glr_fast_fourier_transform_live_002.png
   :alt: FFT of  Signal
   :srcset: /auto_examples/region_of_interest/images/sphx_glr_fast_fourier_transform_live_002.png
   :class: sphx-glr-single-img






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

   **Total running time of the script:** (0 minutes 1.571 seconds)


.. _sphx_glr_download_auto_examples_region_of_interest_fast_fourier_transform_live.py:

.. only:: html

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

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

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

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

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

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

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


.. only:: html

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

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