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Journal: Jan 19, 2009</h1>
<i>Bryan Newbold, <a href="mailto:bnewbold@mit.edu">bnewbold@mit.edu</a></i><br />
<i><a href="http://web.mit.edu/bnewbold/thesis/">
http://web.mit.edu/bnewbold/thesis/</a></i>
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Finished the Seasoned Schemer yesturday. I've been looking through R5RS, it's
great how short it is! (50 pages)
From the scmutils manual:
<blockquote>
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!
</blockquote>
Indeed!
<br /><br />
I also liked this quote from Sean Carrol's Spacetime and Geometry (p485):
<blockquote>
The nice property of tensors, that there is usually only one sensible thing to do based on index placement, is of great help here."
</blockquote>
Sounds like a call for computation?
<hr />
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.
<br />
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.
<br /><br />
<a href="16jan2009.html"><i>(previous entry</i></a>
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