Miroslav Hallo - Software

Plot PT-axes into polar diagram and the triangle diagram

Open source Matlab functions for plotting PT-axes into polar diagram, and triangle diagram (Frohlich 1992) of DC focal mechanisms.

Codes are published under the GNU General Public License (GNU GPL) for non-commercial use.

Methodology following:
  • Frohlich, C. (1992): Triangle diagrams: ternary graphs to display similarity and diversity of earthquake focal mechanisms, Physics of the Earth and Planetary Interiors, 75, 193-198.
List of the functions:
  • PTaxesPlot.m - Plot PT-axes of DC focal mechanisms into the polarplot diagram
  • TrianglePlot.m - Classification of source focal mechanisms (strike-slip, reverse, normal, odd) and plot the triangle diagram.


MATLAB (revision 2/2019):
  • PTplot.zip - Zip package containing all Matlab codes for plotting PT-axes and triangle diagrams
  • MechApp.zip - Zip package containing stand-alone windows application for plotting PT-axes and triangle diagrams


The codes do not require any additional MatLab Toolboxes
The codes were tested on various versions of MatLab software, and it should work without any problems even on older versions. Tested versions: Matlab 2012b 32-bit (Windows 7), Matlab 2018b 64-bit (Windows 7).