I once wrote a procedure for drawing tabulars with square cells; it was one of my earliest experiences with LaTeX programming, actually. When I’d done so, I received a comment ‘why doesn’t LaTeX allow this easily’?

Well, I wondered, why not? My feelings at the time (echoed a little today) were that LaTeX is a tool for writing largely technical documents, and such specific requirements fall outside its regular bounds of ways to typeset tabular material. (Forget, for the minute, that LaTeX’s tables are pretty ugly by default; I’m assuming everybody uses the booktabs package.)

I still agree with the author of booktabs on this matter: ‘It is not going too far to say that if you cannot create a table using the commands in this package, you should redesign it.’ However, I do admit that things like tables with coloured rows and so on do have their uses.

Just recently Karl Berry mentioned he wanted to typeset a grid of images with a large image in the centre. (Not unlike what you see at the top of the page. Just replace the coloured boxes by real images.) This isn’t something that LaTeX does out of the box, and I’m not sure, actually, if any third package can do it either. (I tried but failed with multirow.)

Spurred on by the requisite ConTeXt example that ‘just works’, my own attempt to implement this arrangement turned out to be quite easy but not exactly straightforward. Let me know if there’s a better way.

First of all, the input syntax:

\begin{tighttabular}{@{}c@{}c@{}c@{}c@{}c@{}c@{}}
\1&\1&\1&\1&\1&\1\\
\1&\1&\1&\1&\1&\1\\
\1&\1&  &  &\1&\1\\
\1&\1&\9&  &\1&\1\\
\1&\1&\1&\1&\1&\1\\
\1&\1&\1&\1&\1&\1\\
\end{tighttabular}

Notice that my approach simply puts the material in the lower-left cell in order to fill in the space taken up by the others. This would not work if the cells were of unknown and uneven sizes.

The definition of tighttabular is easy; just define \arraystretch to zero, locally:

\newenvironment{tighttabular}{%
  \def\arraystretch{0}%
  \begin{tabular}%
}{%
  \end{tabular}%
}

How do we place material in that box \9 so it comes out with the correct alignment? Actually, it’s not that bad:

\def\9{%
  \rlap{\smash{\largebox}}%
}

The \rlap first removes the horizontal width, and the \smash removes the vertical height. This is done so that the cell that holds \9 takes up only the same amount of space as the other cells around it. (Otherwise, they would stretch to fit, distorting the size and alignment of the tabular.)

Finally, what is \1 and how do you get the colours to do that?

\def\1{\smallbox}
\def\smallbox{\color{blah!!+}\rule{2cm}{2cm}}
\def\largebox{\scalebox{2}{\smallbox}}

(\scalebox requires the graphicx package.) These boxes use the xcolor package’s very convenient ‘colour series’ feature:

\usepackage{xcolor}
\definecolorseries{blah}{hsb}{step}[hsb]{.5,1,1}{.1,-.05,0}
\resetcolorseries{blah}

And that’s it. Whether you think this whole approach is nice and straightforward or horribly arcane will be somewhat of a personal decision. We’re still awaiting the one tabular package to replace all others in the LaTeX world, although I’m pleased to see recent efforts moving towards providing a complete interface to the different methods supported by the various LaTeX third-party packages in this area.

(With my LaTeX3 hat on: no, as far as I know we’ve not even begun thinking about how this might be dealt with there. I’m not an expert in this area. Although I will say that I mildly dislike both LaTeX’s & and ConTeXt’s \bTR…\eTR syntax; for me, the former is too close to the metal and the latter too verbose.)