Re: Math alignment problem

[Aditya Mahajan <adityam@umich.edu>]

On Sat, 10 Jan 2009, Marcin Borkowski wrote:

> Dnia Sat, Jan 10, 2009 at 01:15:28PM -0500, Aditya Mahajan napisał(a):
>> On Sat, 10 Jan 2009, Marcin Borkowski wrote:
>>
>>> Hi all,
>>>
>>> I'd like to typeset a system of simultaneous equations.  I want it to
>>> have a brace on the left (like "cases"), but inside I want it to have
>>> two columns aligned like "align".  Also, I'd like to have the vertical
>>> space between the equations be small (like in cases), not so big as in
>>> align.
>>>
>>> How to do this?
>>
>> I do not completely understand what you want. Do the following give the
>> desired output.
>
> Sorry;).
>
>> \starttext
>>
>> \startformula
>>   \startcases[align={right,left},distance=3pt]
>>     \NC 2x + 3y \MC{} = 10 \NR
>>     \NC 3x + 2y \MC{} = 5   \NR
>>   \stopcases
>> \stopformula
>>
>> \startformula
>>   \startmatrix[align={right,left},distance=3pt,left={\left\{},
>> right={\right.}]
>>     \NC 2x + 3y \NC{} = 10 \NR
>>     \NC 3x + 2y \NC{} = 5   \NR
>>   \stopmatrix
>> \stopformula
>>
>> \stoptext
>
> Both work just fine, but with distance=0pt instead.  Thanks!  There is
> only a minor problem with the former one: it's somehow shifted to the
> left compared with the latter (both in MkII and MkIV).  I have no idea
> why.

mathcases has a numberdistance key, which adds some width at the end of 
each row. You can set numberdistance to zero.

>> The {} after the alignment \NC is useful if the next symbol is something
>> that can be a uniary or binary symbol (eg, + or -). The {} tells tex to
>> treat is as a binary symbol.
>
> Of course - the {} is an "ord" atom for TeX, AFAIR.
>
>> If you frequently need something like this, you can use
>> definemathcases/definemathmatrix to define a new environment with
>> appropriate parameters.
>
> Yes; however, I'd still have to use the {} after the \NC...

Yes. You can define something like \OC (ord column) to be \NC{}.

Aditya
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
archive  : https://foundry.supelec.fr/projects/contextrev/
wiki     : http://contextgarden.net
___________________________________________________________________________________