Home Page For Snap

Snap is a computer program for studying arithmetic invariants of hyperbolic 3-manifolds. It is based on Jeff Weeks' program SnapPea for studying hyperbolic 3-manifolds, and on the number theory package Pari. Snap uses Pari's high precision arithmetic and number theoretic functions to compute invariant trace fields and related 3-manifold invariants. See the paper, Computing arithmetic invariants of 3-manifolds by Coulson, Goodman, Hodgson and Neumann, Experimental Mathematics Vol.9 (2000) Issue 1 for more about snap, available here in preprint form. See also Neumann and Reid in Topology '90, Proceedings of the Research Semester in Low Dimensional Topology at Ohio State University. Berlin New York: de Gruyter 1992, for more about invariant trace fields and arithmetic invariants of 3-manifolds in general.

NEW: Arithmetic data on knotted graphs available here.

NEW: A paper on Commensurators of cusped hyperbolic manifolds, by Heard, Goodman and Hodgson is available here. (To appear in Experimental Mathematics.)

tables of data on commensurability classes of cusped hyperbolic 3-manifolds are available here.

NEW: To visit the home page for Orb click here.

Source Distribution

Snap (including "tube") is now hosted at SourceForge.

Older versions can be downloaded here:

snap-1.10.2.tar.gz (8.6Mb)

includes the above mentioned preprint and also a number of tables of 3-manifold invariants computed with the help of snap. Snap 1.10 was developed and tested on an Apple G4 running MacOS X version 10.2.8 and compiled with gcc version 3.1. This distribution includes the experimental program "tube".

In order to compile and run this version of snap you will also need a compatible version of Pari, included here for your convenience.

pari-2.1.1.tar.gz (1.5Mb)

Previous version:

snap-1.9.tar.gz (2.6Mb)

Binary Distributions

Please let us know if you require a DEC Alpha version of snap. We no longer have access to a SunOS machine so there will be no new binaries provided for this architecture. The following include the aforementioned preprint and tables of invariants.

snap-1.7.1-SunOS-4.1.3.tar.gz (2.2Mb)

snap-1.7.1-Alpha-OSF1.tar.gz (4.6Mb)

The following includes binaries and tables only.


Windows Distribution

Binaries only (compiled using Cygwin).


Unpack using WinZip or similar utility. To run the binaries, all required files are included.

To compile the source code yourself under Windows you will need Pari (as above) and a C++ compiler. For the latter we recommend you obtain the Cygwin package. Both pari and snap compile "out of the box" under cygwin with options set for static binaries.

Tube Program

Experimental version of a program for computing tube domains. The latest version of this program is now included with snap.

Snap was developed at Melbourne University, with grants from the Australian Research Council. If you have any questions or comments about snap, please contact Oliver Goodman.

Last modified: Tue Jul 26 15:50:30 EST 2005

Department of Mathematics | University of Melbourne