## Beauxindex

Last week I presented a simple script that helped spot almost identical index entries. Since then, I’ve sought a better index style. While I found most book use a rather plain index style, I was looking for something that used space efficiently yet was easy to read.

The idxlayout package will help us customize the index somewhat. It will allow us to set the number of columns, set the distance between them, maybe with a line, set font size, and decide how we want topics arranged. In the image above, I have used the singlepar layout. It is invoked by adding the itemlayout=singlepar option as a package option:

\usepackage[itemlayout=singlepar]{idxlayout}


With an extra bit of configuration somewhere else in your LaTeX source:

\renewcommand{\see}[2]{\mdseries \emph{\seename} #1 }
\renewcommand{\indexsubsdelim}{~\raisebox{0.2ex}{\resizebox{1em}{0.5ex}{$\sim$}}
} % symbol(s) between subtopics
\setkeys{ila}{columns=3} % nb columns
\setkeys{ila}{rule=0pt} % width of line between cols (0=no line)
\setkeys{ila}{columnsep=1em} % spacing between columns
\setkeys{ila}{font=footnotesize} % base font size
\setkeys{ila}{indentunit=1em} % how much to indent after first line
\setkeys{ila}{justific=standard} % raggedright is a mess!
\setkeys{ila}{initsep=0.5em plus 0.5em minus 0.1em} % rubberband length between paragraphs
\printindex


The idxlayout package isn’t very well documented, so you might have to dig in the source code itself to find values that you’re interested in changing. It produces:

Which appears… flat.

These tweak make a much better-looking index than the makeindex default, but there are still a few things to tweak. The thing that bothered me most is that we do not really have a clear separation between the head topic and subtopics. To achieve good visual separation, we must redefine yet more variables. This time in makeindex. However, makeindex customization involves an “index style” file:

\makeindex[options=-s back-matter/index.ist]


The configurable elements are found in makeindex‘s man page. The necessary elements are set in the index.ist file, as follows:

item_0 "\n \\bfseries \\item "
item_1 "\n \\mdseries \\subitem "
item_01 "\n \\mdseries \\indexsubsdelim "
item_x1 "\n \\mdseries \\indexsubsdelim "


The item_0 variable defines the style with which a topic will be displayed. For now, in bold. The item_xy variables define the style change when you go from a level x item to a y level item. Since I want subtopic to appear “normal face”, \mdseries is inserted just before the subitem. The item_x1 seems to be also necessary to ensure that only the first topic in a paragraph is bold.

The changes produce the index as shown in the image at the beginning