[NTG-context] mathmatrix and internal lines

[Otared Kavian]

Hi Jean-Philippe,

A few weeks ago I saw briefly the discussion about Hans' message regarding \noalign and the the new definitions of \HR and \VR that you are sending. Indeed your solution works great !
Just for the case other people may have the same question about writing block matrix, I copy below the whole example which can be found later in the mail archive.
(For mkiv, I don't know how to do the same thing…).

%%% begin block-matrix.tex
% in LMTX defining \HR and \VR to create block matrices:
\pushoverloadmode
\noaligned\tolerant\protected\def\HR[#1]{\noalign{\hrule #1}}
\popoverloadmode

\def\VR{\dosingleempty\doVR}
\def\doVR[#1]{\NC \hskip-0.5em \vrule #1 \hskip-0.5em \NC}

\definemathmatrix[mymatrix]
	[left={\left(\,},
	right={\, \right)}]

\starttext	

\startformula
	\startmymatrix
		\NC A \VR  B \NR
		\HR
		\NC C \VR  D \NR
	\stopmymatrix
\stopformula

\stoptext
%%% end block-matrix.tex

Best regards: Otared K.

> On 26 Nov 2020, at 19:46, Jean-Philippe Rey <jean-philippe.rey at centralesupelec.fr> wrote:
> 
> Hi Otared,
> 
> Thank you very much.
> 
> I used your example to write the following macros. They are far from perfect but suit my needs.  A few days ago, Hans warned not to use \noalign in LMTX, so I used the trick he gave to the list even if I don't really understand it.
> 
> === LMTX version ============
> %D \macros{HR, VR}
> %D \type{\HR} draws a horizontal rule between two rows of a matrix
> %D \type{\VR} is used in place of \type{\NC} to draw a vertical rule between two columns of a matrix
> %D each macro takes an optional parameter giving the rule dimensions
> %D Example
> %D  \type{\startmatrix \NC A \VR[depth 2mm] B \NR \HR[height 0.6pt] \NC C \VR D \NR \stopmatrix}
>  
> \pushoverloadmode
> \noaligned\tolerant\protected\def\HR[#1]{\noalign{\hrule #1}}
> \popoverloadmode
> 
> \def\VR{\dosingleempty\doVR}
> \def\doVR[#1]{\NC \hskip-0.5em \vrule #1 \hskip-0.5em \NC}
> ===========================
> 
> === MkIV version ============
> %D \macros{HR, VR}
> %D \type{\HR} draws a horizontal rule between two rows of a matrix
> %D \type{\VR} is used in place of \type{\NC} to draw a vertical rule between two columns of a matrix
> %D it takes an optional parameter giving the rule dimensions
> %D Example
> %D  \type{\startmatrix \NC A \VR[depth 2mm] B \NR \HR \NC C \VR D \NR \stopmatrix}
>  
> \def\HR{\noalign{\hrule}}
> 
> \def\VR{\dosingleempty\doVR}
> \def\doVR[#1]{\NC \hskip-0.5em \vrule #1 \hskip-0.5em \NC}
> ===========================
> 
> For the MkIV version I haven't been able to add an optional parameter to \HR the code
> 
> \def\HR{\dosingleempty\doHR}
> \def\doHR[#1]{\noalign{\hrule #1}}
> 
> complains about "Misplaced \noalign"
> 
> Best regards,
> 
> 
> 
>> Le 26 nov. 2020 à 13:40, Otared Kavian <otared at gmail.com> a écrit :
>> 
>> Hi Jean-Philippe,
>> 
>> The following is better than the one I sent earlier:
>> 
>> \definemathmatrix[mymatrix]
>> 	[left={\left(\,},
>> 	right={\ \right)}]
>> 	
>> \starttext
>> \startformula
>> 	\startmymatrix
>> 		\NC A \NC\hskip-.5em \vrule  \NC\hskip-.5em B \NR
>> 		\noalign{\hrule}
>> 		\NC C \NC \hskip-.5em\vrule \NC \hskip-.5em D \NR
>> 	\stopmymatrix
>> \stopformula
>> \stoptext
>> 
>> Best regards: Otared K.
>> 
>>> On 26 Nov 2020, at 10:19, Jean-Philippe Rey <jean-philippe.rey at centralesupelec.fr> wrote:
>>> 
>>> Dear list,
>>> 
>>> I would like to draw matrices with internal lines as can be done with LaTeX (cf pdf output) :
>>> 
>>> ========================
>>> \documentclass{article}
>>> \begin{document}
>>> $M =\left( \begin{array}{c|c}
>>> A & B \\
>>> \hline
>>> C & D \\
>>> \end{array} \right)$
>>> \end{document}
>>> ========================
>>> 
>>> I didn't find out how to use mathmatrix to achieve this. My best result to date is 
>>> 
>>> ========================
>>> \starttext
>>> $M = \left( \bTABLE[frame=off]
>>> \bTR
>>> 	\bTD[rightframe=on, bottomframe=on] $A$ \eTD
>>> 	\bTD[bottomframe=on] $B$ \eTD
>>> \eTR\bTR
>>> 	\bTD[rightframe=on] $C$ \eTD
>>> 	\bTD $D$ \eTD
>>> \eTR
>>> \eTABLE \right)$
>>> \stoptext
>>> ========================
>>> 
>>> The code is rather ugly, and I get a spurious space at the bottom of the table.
>>> 
>>> Any hints?
>>> 
>>> Thank you,
> 
> -- 
> Jean-Philippe Rey
> jean-philippe.rey at centralesupelec.fr
> 91192 Gif-sur-Yvette Cedex - France
> Empreinte PGP : 807A 5B2C 69E4 D4B5 783A 428A 1B5E E83E 261B BF51
> 
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