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Is there a good program that runs on Mac OSX, which has a graphical interface for inputting knot or link diagrams, and calculates standard invariants like the Conway and Jones polynomials?

I have been using the Mathematica knot theory package pioneered by Dror Bar-Natan, but it doesn't do graphical entry, and I want to move away from Mathematica which is expensive, and I can't expect my students to buy. I have also used Hoste and Thistlethwaite's knotscape program, which is a unix program, and I suppose that it might be installable on OSX, since OSX is basically unix underneath, but I'm not enough of a computer guru to figure out how to do that. I was hoping someone has developed a program that runs right on OSX, but if not, I'll try to see if I can get knotscape to work.

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I wish I could offer a bounty for someone to develop such a program. :) –  Grumpy Parsnip Nov 13 '11 at 20:07
You can enter the knots in with SnapPy, export the triangulation to Regina and compute the Alexander polynomials and Alexander modules with that. –  Ryan Budney Nov 15 '11 at 4:41
Thanks for the tip, Ryan. –  Grumpy Parsnip Nov 15 '11 at 17:48
Caveat - I think the alexander polynomial code isn't finished for 3-manifold triangulations yet... but it works fine for 4-manifold triangulations. I'll update you when I've finished the code for 3-manifolds. Maybe that will be by Christmas, but more likely it'll be in March. –  Ryan Budney Nov 15 '11 at 18:10
@Ryan: Departments need better recognition of program development as a sign of research productivity, since it is often even more of a service to the community than traditional publications. –  Grumpy Parsnip Nov 15 '11 at 22:36
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2 Answers

up vote 1 down vote accepted

I'm currently using KnotPlot and it is installable on OsX. The full version is only $29.99 USD.

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I just purchased it and I'm testing it out. It's quite a neat program. The one downside is that the Alexander polynomial module depends on the user having Maple or Mathematica installed. On the other hand, the Conway polynomial is a specialization of the HOMFLY polynomial, which the program calculates fine, so maybe this won't be a big deal. I'm going to wait to award the bounty for a few days in case someone has an even better answer. –  Grumpy Parsnip Nov 15 '11 at 22:35
Sure, no problem. –  user02138 Nov 15 '11 at 23:01
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there is an OSX version of knotscape available here: http://pzacad.pitzer.edu/~jhoste/HosteWebPages/downloads/Knotscape-noLinks.tar.gz

Note that it is a PPC version, so you need either an old Mac, or a PPC emulator (there exist such an emulator for OSX 10.6, available from Apple, not sure if you would have luck with newer versions of OSX though).

One should encourage knotscape authors to release the source, otherwise it's all but dying...

EDIT: the source is actually available, it is included in the binary archives on the main knotscape page.

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