From: David Kastrup <dak@gnu.org>
Subject: Re: Non-Commutative calculations in Calc, Revisited
Date: Thu, 06 Oct 2005 15:42:40 +0200 [thread overview]
Message-ID: <851x2yu5gv.fsf@lola.goethe.zz> (raw)
In-Reply-To: 878xx66b1c.fsf@vh213602.truman.edu
Jay Belanger <belanger@truman.edu> writes:
> Neon Absentius <absent@sdf.lonestar.org> writes:
>
>> When in non-commutative (aka `matrix') mode calc calculates
>> (a b)^-1 to be a^-1 b^-1 instead of the correct b^-1 a^-1.
Uh, what's correct about b^-1 a^-1?
Set a=[1,1], b=[1;0], then (a b)^-1 = [1], and neither b^-1 nor a^-1
exist.
This only works with a and b being square matrices.
--
David Kastrup, Kriemhildstr. 15, 44793 Bochum
next prev parent reply other threads:[~2005-10-06 13:42 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <mailman.9745.1128461080.20277.help-gnu-emacs@gnu.org>
2005-10-06 13:16 ` Non-Commutative calculations in Calc, Revisited Jay Belanger
2005-10-06 13:42 ` David Kastrup [this message]
2005-10-06 16:17 ` Jay Belanger
2005-10-06 18:23 ` Neon Absentius
2005-10-06 18:01 ` Neon Absentius
2005-10-07 0:47 ` Neon Absentius
[not found] ` <mailman.10168.1128646105.20277.help-gnu-emacs@gnu.org>
[not found] ` <wi7jcqt9ep.fsf@dms.auburn.edu>
2005-10-07 2:15 ` Neon Absentius
[not found] ` <mailman.10178.1128651397.20277.help-gnu-emacs@gnu.org>
2005-10-07 7:26 ` David Kastrup
[not found] ` <mailman.10119.1128621714.20277.help-gnu-emacs@gnu.org>
2005-10-07 3:59 ` Jay Belanger
2005-10-07 21:31 ` Jay Belanger
2005-10-04 21:23 Neon Absentius
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