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Steca: the stress and texture calculator

The stress and texture calculator Steca is an interactive, graphical data reduction program for neutron and x-ray materials diffractometers.


Version 2.0.5 has been released on Dec 6, 2017. See the change log.


The code, and a Windows executable, are available at

Bugs and feature requests are collected at

To stay informed about new releases, and to participate in discussions between developers and users, please subscribe to the Steca mailing list.

License and Citation

Redistribution of the software is permitted under the terms of the General Public License version 3 or higher.

In scientific publications, the use of Steca must be acknowledged and documented in form of these two citations.


The current maintainer is Joachim Wuttke,


imagediffractogrampole figure

Steca processes histogram data collected by area detectors. The user defines gamma cuts for which diffractograms are computed. The user then selects Bragg peaks, which are usually analyzed by curve fitting. Peak positions, widths, and intensities can then be tabulated against input parameters, or converted into pole figures.

Steca is developed primarily to support the STRESS-SPEC diffractometer at MLZ Garching.

The main functions of Steca are:

  • Import of histograms and associated metadata from data files.
  • Variable grouping of multiple data sets.
  • Correction of unequal detector pixel sensitivity.
  • Calculation of diffractograms, either from complete images or from image “slices” with specified range of γ.
  • Semi-automatic diffractogram peak fitting.
  • Calculation of pole figure points and their interpolation.
  • Calculation of diagrams that show dependencies between imported metadata and calculated data.
  • Export of results in various data formats for further processing.

Version 1, spelled STeCa, has been developed by Christian Randau, see the JAC article by C. Randau, U. Garbe and H.-G. Brokmeier. For more details, see also his PhD thesis.

Version 2 has been developed by Rebecca Brydon, Jan Burle, Antti Soininen, and Joachim Wuttke of the Scientific Computing Group of JCNS at MLZ Garching. It has a newly designed user interface. Core calculations were re-implemented for increased speed. The imported and computed data can be interactively manipulated and inspected. The code has been written to allow long-term maintenance, further development and extensions, and future support of new data formats.

Documentation pages