# [texhax] 3x3 array of alighned equations

Wed Nov 2 13:43:50 CET 2005

Novak Elliott :

> Hi,
>
> I'd like to format a 3x3 array of subequations in the form:
>
> a11 = b,         a12 = c,    a13 = d             (1a,b,c)
>                                                  -
>                                                  e
>
> a21 = f,    3 x a22 = ...                             (1d,e,f)
>          -
>          g
>
> a22 = ..                                                     (1g,h,i)
>
> i.e. I want them aligned horizontally between the three columns and also I want them aligned to the = sign within each column.  So I effectively have 9 columns, or 3 columns each with 3 subcolumns.  The eqnarry environment only allows the alignment to work with one equation per line, and the array environment typesets fractions in a tiny font so that they fit within one text line.  However, I want them to be at full size like in an ordinary equation.  I have a hack for getting the subequation numbering to work without using the subequations environment so that shouldn't be a drama.  If there is a way to produce an array that allows left/centre/right alignment and also allows fractions to be typeset at full size then that would almost certainly work.
>

the amsmath package and the alignat env might help

\begin{alignat*}{3} % three alignments
a&=b & &=c & &=d\\
a&=bbbb & &=c & &=d\\
a&=bb & &=c & &=d
\end{alignat*}

there needs to be 2n-1 &'s in each line, where n is the number of
alignments, the extra two &'s in the example above separates the
alignments.

/daleif

You cannot help men permanently by doing for them
what they could and should do for themselves. ''
-- Abraham Lincoln