Re: [Maxima-discuss] bug in tex for a matrix

[Michel G. <mg...@gm...>]

The workaround works great. (\setcounter..°
Thanks very much

Le jeu. 24 avr. 2025 à 17:13, Leo Butler <Leo...@um...> a écrit :

> On Wed, Apr 23 2025, Robert Dodier <rob...@gm...> wrote:
>
> > On Wed, Apr 23, 2025 at 12:38 PM Leo Butler <Leo...@um...>
> wrote:
> >>
> >> This is a limit in tex:
> >>
> >>
> https://stackoverflow.com/questions/2789416/typesetting-a-large-matrix-in-latex
> >>
> >> The solution, made clear in the second answer, is to do something like
> >>
> >> \setcounter{MaxMatrixCols}{30}
> >>
> >> See also: https://sourceforge.net/p/maxima/bugs/4332/#7f8b
> >
> > There is a different implementation of TeX output for a matrix in
> > share/utils/mactex-utilities.lisp, which makes use of \begin{pmatrix}
> > and \end{pmatrix}. I think load("mactex-utilities.lisp") should find
> > it. Does that obviate the problem with the maximum number of columns?
>
> No, it does not, as you can confirm by loading that package into an
> imaxima session and creating a matrix with ≥ 10 columns (the SO question
> I cite found the problem using the amsmath `bmatrix' environment.)
>
> The following does work (again, tested using imaxima):
>
> texput(matrix,lambda([expr],
> printf(false,"\\setcounter{MaxMatrixCols}{~a}\\begin{pmatrix}~%~{~{~a~^&~}~^\\\\~}~%\\end{pmatrix}",length(first(args(expr))),map(lambda([row],map(tex1,row)),args(expr)))))
> $
>
>
> >
> > I gather that \begin{pmatrix} / \end{pmatrix} is from AMSTeX. Is that
> > a reason to avoid it?
>
> I guess this is a perennial question about the `tex' command; the
> command's name suggests that it should emit valid TeX (\pmatrix //
> \endpmatrix), not LaTeX (\begin{pmatrix} // \end{pmatrix}).
>
> The current version of mactex.lisp does use \pmatrix if it is available.
>
> > Should we consider moving TEX-MATRIX from
> > share/utils/mactex-utilities.lisp to src/mactex.lisp?
>
> I don't think so. Although it is easier to read the output, it violates
> the presumption that `tex' generates valid TeX.
>
> The same SO link suggests using the `+bmatrix' environment from the
> tabularray package. Apparently, this obviates the need to set
> `MaxMatrixCols'.
>
> Leo