On Fri, May 23, 2014 at 11:54 AM, Matthias Weber <matweber@indiana.edu>wrote:

> Dear All,
>
> I would like to define a command that expands
>
> \vector{2,4} % or vector[2,4] if that’s easier
>
> to
>
> \startpmatrix
>  \NC 2 \NR
>  \NC 4 \NR
> \stoppmatrix
>
> and more generally
>
> \vector{2,4,1,7}
>
> to
>
> \startpmatrix
>  \NC 2 \NR
>  \NC 4 \NR
> \NC 1 \NR
> \NC 7 \NR
> \stoppmatrix
>
> Any hints how to achieve this?
>
> Thanks,
>



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

\startluacode
document = document or {}
document.matthias =  document.matthias or {}
local function lua_columnvector(a)
 context.startpmatrix()
  for i,v in ipairs(a) do
     context.NC() context(tostring(v))  context.NR()
 end
 context.stoppmatrix()
end
document.matthias.lua_columnvector = document.matthias.lua_columnvector  or
lua_columnvector
\stopluacode

\def\columnvector#1{\ctxlua{document.matthias.lua_columnvector(#1)}}

\starttext
\startformula
\columnvector{{1,2,3}} %% watch the double { !
\stopformula


\stoptext

-- 
luigi