:tocdepth: 1

.. _human-interactivity:

===================
Human interactivity
===================

**Key paper:** S. Lee *et al.*, `Interactive framework for real-time 4D-STEM analysis and reconstruction <https://doi.org/10.1093/mam/ozag053.941>`__, *Microscopy and Microanalysis* 32 (Suppl. 1) (2026)

A framework for human interactivity lets scientists develop algorithms and analyze multidimensional data with real-time feedback at 60 to 120 frames per second: seeing results as they are computed, adjusting parameters, and steering the analysis. Electron microscopy is one application, and **quantem.widget** is its implementation, running in Jupyter or as standalone WebGPU pages on a workstation, cluster, laptop, or phone.

.. figure:: ../img/research/interactive-framework.png
   :width: 90%
   :align: center
   :alt: Schematic of interactive widgets connecting 4D-STEM algorithms, researchers, and microscopes

   **Interactive widgets bridge 4D-STEM algorithms, researchers, and microscopes** for real-time feedback: algorithms stream results to the widgets, and the researcher's input flows back as new parameters and as detector and scan control.

quantem.widget includes:

- `Show4DSTEM <https://electronmicroscopy.github.io/quantem.widget/tutorials/show4dstem.html>`__: live virtual detectors and `WebGPU HTML export <https://electronmicroscopy.github.io/quantem.widget/tutorials/show4dstem_export.html>`__
- `Show2D <https://electronmicroscopy.github.io/quantem.widget/tutorials/show2d.html>`__: images, contrast, FFTs, ROIs, and profiles
- `Show3D <https://electronmicroscopy.github.io/quantem.widget/tutorials/show3d.html>`__ and `Show3DSlices <https://electronmicroscopy.github.io/quantem.widget/tutorials/show3dslices.html>`__: stacks and volume slices
- `ShowDiffraction <https://electronmicroscopy.github.io/quantem.widget/tutorials/showdiffraction.html>`__: diffraction spots, rings, spacings, and angles
- `ShowPtycho <https://electronmicroscopy.github.io/quantem.widget/api/showptycho.html>`__: SSB phase and aberration review

.. figure:: ../img/research/show4dstem-demo.gif
   :width: 100%
   :alt: Show4DSTEM widget with a diffraction pattern and live virtual detector image

   **Show4DSTEM** in the browser with WebGPU. Liquid-cell Au nanoparticle data courtesy of Serin Lee (`paper <https://academic.oup.com/mam/article-abstract/32/3/ozag044/8701498>`__, `data <https://zenodo.org/records/18167694>`__).

The interactivity framework has supported the development and adoption of these electron microscopy algorithms:

- **Drift correction** of 2D images, spectrum images, and 4D-STEM datasets (see :ref:`drift-correction`)
- **ACOM** (automated crystal orientation mapping) from 4D-STEM diffraction
- **MAPED** (multi-angle precession electron diffraction)
- **Strain mapping** from 4D-STEM nanobeam diffraction
- **Lattice finding**
- **PDF** (pair distribution function) analysis

`Code <https://github.com/electronmicroscopy/quantem.widget>`__ · `Documentation <https://electronmicroscopy.github.io/quantem.widget/>`__

Co-authored publications
------------------------

- **Interactive framework for real-time 4D-STEM analysis and reconstruction.** S. Lee *et al.*, `Microscopy and Microanalysis <https://doi.org/10.1093/mam/ozag053.941>`__ 32 (Suppl. 1) (2026).
- **Optimizing strain mapping using nanobeam diffraction in 4D-STEM.** `Microscopy and Microanalysis <https://doi.org/10.1093/mam/ozag053.028>`__ 32 (Suppl. 1) (2026). A new method that improves the precision of strain reconstruction from 4D-STEM nanobeam diffraction, where Bragg-disk localization is limited by scattering and background noise.