Subject: Relativistic addition of velocities in wxMaxima
From: Raymond Toy
Date: Tue, 24 Sep 2013 09:39:06 -0700
>>>>> "laurent" == laurent couraud <l.couraud at gmail.com> writes:
laurent> Hi everyone!
laurent> ?
laurent> i meet the following strange behavior:
laurent> ?
laurent> Maxima 5.31.0 http://maxima.sourceforge.net
laurent> using Lisp GNU Common Lisp (GCL) GCL 2.6.8 (a.k.a. GCL)
laurent> Distributed under the GNU Public License. See the file COPYING.
laurent> Dedicated to the memory of William Schelter.
laurent> The function bug_report() provides bug reporting information.
laurent> (%i1) x^2;
laurent> ??????????????????????????????????????????????????????????? 2
laurent> (%o1)????????????????????????????????????????????????????? x
laurent> (%i2) subst(1e-3,x,%o1);
laurent> (%o2)??????????????????????????????????????????????????? 0.0E-7
Ah, this is probably a roundoff issue combined with a printing issue
with gcl. What value is actually computed in %o2? Probably something
like 0.999999e-6?
(I don't have a gcl build right now.)
Ray