Dr. Frederick W. Vollmer

Software

As a structural geologist, I spend my time studying and enjoying rock structures from microscopic crenulations to great rifts and mountain belts. I am, however, a compulsive computer programmer. The first geological software I wrote was a strain analysis program for Win Means, using punch cards and Fortran on a 1970s era mainframe. Computers and computing power quickly advance, and I have since used numerous compilers and languages. All of my software is compiled natively on Windows, Macintosh, and Linux, giving optimal performance on each platform.

This software is free, but is not public domain, and may not be redistributed or posted elsewhere without permission. The only stipulation is that use of the software in analyzing data or preparing diagrams must be cited in publications, presentations, reports, or other works. It is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose. Please read the Users Manuals for details on licensing and citation.

If you use the software on a regular basis, and wish to support its continued development and free distribution, please consider making a donation.



Orient Orient is for analyzing orientation data, data that can be described by an axis or direction, or by a position on a sphere or circle. Examples include latitude and longitude, star locations, bedding planes, fold axes, fault slip directions, paleomagnetic vectors, glacial striations, crystallographic axes, current flow directions, and animal migration paths. Orient is used by many geologists, but is developed to be flexible for use in other disciplines requiring orientation data plotting and analysis.
EllipseFit EllipseFit is an integrated program for two and three-dimensional geological fabric and finite strain analysis. Sample distributions of points, lines, ellipses, polygons, and arbitrary shapes are digitized from oriented photographs to determine mean fabric and finite strain ellipses and ellipsoids. It is designed for field and laboratory structural geology studies, and is also ideal for teaching introductory or advanced structural geology laboratories.
Antevs Antevs, Automated Numerical Time-series Evaluation of Varying Sequences, is a program for analyzing varve, tree-ring, and other time-series data. The program uses Fourier analysis, or other curve fitting algorithms, to remove trends and to normalize the data for comparison. The resulting data series are correlated using cross-correlation techniques to identify potential matches. Editing capabilities allow series renumbering once an unknown series is correlated with a known chronology.

These open source projects on GitHub include critical published algorithms used in Orient and EllipseFit:

  • SphereContour C, Pascal, and MATLAB programs for automatic contouring of spherical orientation data using a modified Kamb method (Vollmer, 1995).
  • HyperContour MATLAB/Octave script for contouring fabric and finite strain data on the unit hyperboloid (Vollmer, 2018).

Please include these citations when using the code, algorithm, or derivative works to produce figures or other content.



Gallery Gallery - Photographic accounts of various trips I have taken, a mix of geology excursions, road trips, motorcycle journeys, and backpacking trips. Many may be only of interest to friends, family and students, however I use many of the images in my lectures, and these may be of wider scenic or scientific interest.
Rides Motorcycle Roads - A list of 30 classic North American motorcycle roads. The list is compiled from other lists of top American motorcycle roads published by motorcycle magazines, motorcycle groups, travel magazines, books, and other sources. The listed rides include only those that I have personally ridden. It was compiled it while planning for upcoming rides, I hope it may inspire others!