On Thu, 9 Oct 2014, Hans Hagen wrote:

> On 10/7/2014 8:06 PM, Thangalin wrote:
>> Looks like a bug; adding blank rows works around the problem (but
>> looks terrible):
>>
>> \definemathmatrix[pmatrix] [left={\left(\,},right={\,\right)}]
>>
>> \starttext
>> Digueu quines de les matrius següents són regulars. Quan ho siguin,
>> trobeu la inversa
>>
>> \startitemize[a,columns,four]
>> \item \startpmatrix[n=4]
>> \NC \NR
>> \NC 2 \NC 3 \NR
>> \NC 6 \NC 7 \NR
>> \NC \NR
>> \stoppmatrix
>>
>> \item \startpmatrix[n=4]
>> \NC 3 \NC 2 \NC 1 \NR
>> \NC 4 \NC 5 \NC 3 \NR
>> \NC 5 \NC 0 \NC -2 \NR
>> \NC
>> \stoppmatrix
>>
>> \item \startpmatrix[n=4]
>> \NC 5 \NC 4 \NC 2 \NR
>> \NC 2 \NC 2 \NC 3 \NR
>> \NC 7 \NC 6 \NC 5 \NR
>> \NC
>> \stoppmatrix
>>
>> \item \startpmatrix[n=4]
>> \NC a \NC 0 \NC 0 \NC 0 \NR
>> \NC 0 \NC b \NC 0 \NC 0 \NR
>> \NC 0 \NC 0 \NC c \NC 0 \NR
>> \NC 0 \NC 0 \NC 0 \NC d \NR
>> \stoppmatrix
>>
>> \stopitemize
>>
>> \stoptext
>
> not a bug ...
>
> (1) the matrix is centered around the math axis and has equal height and 
> depth so indeed in columns that will not align horizontally

IIRC, we had added a `location=(high|middle|low)` key to change that 
behaviour. (Sorry, cannot test right now).

Aditya