Subject: Re: bug#41223: 28.0.50; Calc gives wrong determinant for some matrices with symbolic variables
From: Mattias Engdegård <[email-masked]>
To: Mauro Aranda <[email-masked]>
Cc: [email-masked]
Date: Thu, 14 May 2020 10:43:19 +0200
List-Id: <debbugs-submit.debbugs.gnu.org>

14 maj 2020 kl. 00.15 skrev Mauro Aranda <[email-masked]>:

> It is good enough for me.  Thanks.

The pleasure was all mine! It has now been pushed to master.

No doubt there are better ways of computing the determinant for non-numeric matrices. In particular, division shouldn't be necessary at all, and the current algorithm results in some untidy expressions. For example, the determinant of

[a 0 0 1]
[0 b 0 0]
[0 0 c 0]
[1 0 0 d]

is given as abc*(d-1/a), falsely giving the impression of being undefined for a=0, rather than bc(ad-1).