Dear Anvita, dear Steve, > On 24.10.2015, at 09:13, Stephen Linton <s...@st-andrews.ac.uk> wrote: > > Dear Anvita, > > This looks like a bug at the very least in the sense that a better error > message should be produced. > M is constructed here in a compressed form, and I am not sure it is possible > to transpose a matrix destructively in that form.
Yet the documentation of TransposedMatDestructive does not mention any restrictions of that kind, so it is a bug in GAP. I logged a bug report for this now: https://github.com/gap-system/gap/issues/303 There is also a related issue: TransposedMatDestructive does not work for immutable matrices, even though the documentation suggests that it does. Of course that may just be a bug in the documentation. > > On the other hand, this form is quite space efficient, so making a copy with > TransposedMat and then letting the garbage collector get rid of the old copy > shouldn’t be too bad. In particular it probably uses less memory that > converting the matrix to a different form and then transposing it. Depending on what you do, another alternative might be to use the cvec package: http://gap-packages.github.io/cvec/ It provides very efficient routines to work with matrices over finite fields, and in particular, can efficiently transpose matrices in-place. Best wishes, Max _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum
