Sorry to insist. I really do not like the keyword algorithm here. The
fact that the output is a unimodular matrix has nothing to do with the
algorithm used to generate it!
On the ambiguity for unimodular, I agree and it fits with the wikipedia
definition: square integer matrix with det +1 or -1.
Vincent
On 09/04/15 10:44, John Cremona wrote:
I suggest that to start with we just correct the documentation, since
there will be code out there which relies on the det being +1. (Of
course I agree with you on the standard meaning of "unimodular".)
John
On 9 April 2015 at 07:10, Jori Mantysalo <[email protected]> wrote:
Matrix.random(ZZ, ..., algorithm='unimodular') works just as the
documentation says: generates a matrix with determinant +1. On the other
hand, unimodularity on ZZ is normally defined as having determinant +1 or
-1.
Should we 1) leave this as it is, 2) correct the code or 3) add some kind of
warning to documentation?
(Also I guess there is faster ways to generate random unimodular matrix than
current implementation. For example by making upper and lower triangular
matrices with +/- 1 on diagonal and multiplying them; but of course it is
not enought because then every matrix will have +1 or -1 as an element, so
they are not that random.)
--
Jori Mäntysalo
--
You received this message because you are subscribed to the Google Groups
"sage-devel" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-devel.
For more options, visit https://groups.google.com/d/optout.
