Journal: Jan 19, 2009

Bryan Newbold, bnewbold@mit.edu
http://web.mit.edu/bnewbold/thesis/

Finished the Seasoned Schemer yesturday. I've been looking through R5RS, it's great how short it is! (50 pages) From the scmutils manual:

Some structures, such as the ones that represent inertia tensors, must be inverted. (The "m" above may be an inertia tensor!) Division is arranged to make this work, when possible. The details are too hairy to explain in this short document. We probably need to write a book about this!

Indeed!

I also liked this quote from Sean Carrol's Spacetime and Geometry (p485):

The nice property of tensors, that there is usually only one sensible thing to do based on index placement, is of great help here."

Sounds like a call for computation?

I've been working on a sage/scheme interface a bit. The problem i'm running into now is disabling the interrupt REPL in MIT/GNU Scheme; I just want it to leave an error string and drop back to the base REPL. I could edit the pexpect routines in sage to try and catch all the pretinent interrupt strings, but I think it would be better to just have the error interrupt hook in scheme do the simple thing.
For now, i'm actually going to switch over to the "scm" scheme distribution which is much simpler and get that going well with sage, then try MIT/GNU scheme again.

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