Department of Mathematics
XTrain is a Java 1.5 implementation of the Bestvina-Handel algorithm for homeomorphisms of surfaces with one puncture. Moreover, XTrain also computes triangulations of mapping tori of surface homeomorphisms, suitable for Jeff Weeks's program SnapPea. Surface homeomorphisms can be entered as a composition of Dehn twists with respect to a great variety of curves, or in terms of the induced automorphism of the fundamental group. XTrain was covered in depth here and here.
XTrain is written in Java and should run on all major operating systems.
Just download the file
xtrain.jar (attached below) and
double-click on it to launch XTrain. XTrain is covered by the GNU
General Public License. Please don't hesitate to contact me if you have
Click here for information on some advanced features of XTrain.
- Added computation of powers to user interface (October 17, 2009)
- Changed font to monospaced for improved legibility
- Added computation of (reduced) characteristic polynomial, generation of random automorphisms, improved user interface
- Replaced ad-hoc linear algebra routines with JAMA package, added GUI support for matrix export (June 04, 2009)
- Tuned numerical routines to handle all Lorenz knots in the cusped census (May 23, 2009)
- Added support for monodromies of Lorenz knots (May 20, 2009)
- xtrain.jar : XTrain executable jar file