For the past few years I have been developing a package called MAF which is a reimplementation in C++ of KBMAG. It extends KBMAG in several ways, and is usually, though not always, a lot faster than it. For example it can calculate the automatic structure of F(2,9) in 10-15 minutes (depending on CPU speed) and the geodesic automatic structure in about 90 minutes. It can find automatic structures or confluent rewriting systems for many challenging presentations. Its functionality can also be used via a library. For example I use it in a screen saver type program to find automata for randomly chosen hyperbolic and kleinan groups of various kinds and then use the automata to draw pretty pictures. In some cases the groups have automata which it would be difficult to create with KBMAG.
You can find out more about MAF on my web site at http://www.alunw.freeuk.com/MAF/maf.html . The FSA code might well be useful for applications other than group theory. I have developed the package on a Windows based machine, but it should be fairly easy to port to other platforms. (On Windows most of the code is in a DLL, and I would like to use a shared object on Linux/ Unix, but am not quite sure of the details - in the past I have created .so files using C, but not C++ and am anticipating there will be tricky issues with "name mangling". On Windows I also replaced most of the CRT. On Unix/Linux the package could use the standard CRT but this would probably result in a considerable increase in memory usage as I provided a heap which is a lot better than the one that usually comes with CRTs - for allocations up to about 1600 bytes it uses a scheme which has an overhead of just over 1 bit per allocation instead of the typical 8 bytes, and as my program might easily need to make in excess of a 100 million memory allocations this overhead is very significant) I'd be happy to make the code available to Sage (about which I know pratically nothing - I am following a suggestion in positing here). I don't know much about open source licensing. The only conditions I want to impose are: 1) Anybody should be free to reuse my source code in non-commercial software, change it in anyway they like and should not have to make their program open source in order to do so. 2) Anybody should be free to reuse my code in commercial software, except for software which is principally concerned with the creation of fractals, tessellations, and related mathematical imagery. For commercial software of that nature I'd want to receive some payment, as I have probably spent several man years developing this library and that is how I intend to use it. For other types of software an acknowledgement and a link to my web site would be enough. I'd also be happy to donate my code to Sage as-is on a one off basis, provided my rights to my own work are not affected in any way - I am still developing the code with the aim of making it both smaller and faster so that it can tackle more and more challenging presentations. Of course there may already be much better alternatives to what I have written... --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
