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Re: Can one do \bordermatrix in MathML?

From: William F Hammond <hammond@csc.albany.edu>
Date: Tue, 02 Nov 2010 14:38:32 -0400
To: David Carlisle <davidc@nag.co.uk>
Cc: W3C MathML Discussion <www-math@w3.org>
Message-ID: <i7k4kvy3iv.fsf@hilbert.math.albany.edu>
David writes:

> Hmm sometimes a recursive structure is more natural but here actually
> I think the spanning structure is closer to teh semantic, as it places
> the column labels in the labelled columns, whereas the alternative you
> propose just has them floating free and just visually aligned rather
> than being tied to the column by markup.

What I think I would really like is "msubtable" with decoration
attributes, say, "overdecor", "rightdecor", "underdecor", and
"leftdecor".  So in this case

  <msubtable leftdecor="(" rightdecor=")"> ... </msubtable>

There could be an attribute for "mtable" that labels it a subtable.

> I have to agree though this has the distinct advantage of working
> whereas the version I offered currently only works in mathplayer of
> the common browsers. You cheat a bit here (only a bit:-) by knowing
> the widths in advance, but perhaps with a bit of javascript measuring
> the widths could be automatically deduced after setting the main
> matrix to its normal width.

Actually, knowing the widths is font-specific, hence, platform and
user specific, so the scheme I suggested is not robust.

>> P.S.  Am I correct in perceiving the border labels as not
>> mathematically semantic?  If so, probably the 2x2 outer array
>> should be an ordinary html table.
>
> If that is the whole display then perhaps, but if it is embedded in a
> larger expression then doing it all in mathml makes sense I think.

On the other hand, to the extent that the border labels are not
mathematically semantic, if one is willing to have rules rather than
parentheses, then the whole thing could be a 4x4 table with inline
math in the cells (except maybe for the border cells).

See  http://math.albany.edu/~hammond/mmlmisc/bordermx2t.xhtml
and  http://math.albany.edu/~hammond/mmlmisc/bordermx2t.html  (html5)

This should not depend on user choice or platform.

Source appended below.

                                    -- Bill

-------------------------------------------------------------
\documenttype{article}
\surtitle{MathML Example}
\title{Another BorderMatrix Example}
\begin{document}

Make the whole thing a $4\times;4$ ordinary table using table
rules with inline math in the cells except for the first row
and first column:
\begin{display}
\begin{tabular}{c|ccc}
~    &   a   &   b   &   c   \\
\hline
x    &  $1$  &  $2$  &  $3$  \\
y    &       & $22$  & $33$  \\
z    &       &       & $333$
\end{tabular}
\end{display}

\end{document}
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Received on Tuesday, 2 November 2010 18:39:02 GMT

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