Hints, Tips & Utilities

Know something useful about Unix, emacs, prolog or any of the myriad other computer programs we 
suffer from in Informatics? Share your knowledge, and receive not only a warm sense of fulfillment that 
at last your life has some purpose, but also a bottle of wine.

 In this issue, we have a handy shell script for choosing the right printer and some LaTex tricks.

Automatically choose the nearest printer
Put this line:
. /usr/local/dai/docs/groups/aisoc/printer.sh
in your .xinitrc file, and your default printer will be set to the nearest one.
Important: don't leave out the "." at the beginning.
If you don't trust us not to insert malicious code later, you can download your own copy of the script.
- Seth Golub


               LaTeX Tricks

LaTeX is capable of most things but not always in the most obvious manner. Here are some useful 
tricks that you might struggle to find in the documentation. I'm not trying to teach you LaTeX there 
are two routes to that 1) read Lamport's book (or something similar) and 2) deconstruct other peoples 
documents and then try writing your own. The department guide LaTeX for the horrified is a 
reasonable place to start (see http://www.dai.ed.ac.uk/dai/computing/software_manuals/latex/).

Dynamically Including Program Listings

You have written the perfect program wonderful.cc and want to include it your report. Well you could do 
\begin{verbatim}
-- Copy and paste your program to here --
\end{verbatim}
However what happens when you suddenly find that your program has a bug or would be even better 
with some tweak. Then you would have to delete the copy from your report and repaste the new version. 
In preference you can use the verbatim package. This allows you to have a file printed in verbatim 
format (ie. looking like a typewriter) at the chosen point of your report.

At the head of your document (somewhere before 

\begin{document}
put the line 
\usepackage{verbatim}
Then in the relevant location put 
\verbatiminput{/hame/perfect/wonderful.cc}
Now if you change your program rerun LaTeX will produce your report with the updated program. 

Rotating Tables and Figures

You want to include the amazing results that you achieve with the program you wrote. No problem, just 
put them in a table. Unfortunately with all the conditions and outputs that you need to include you find 
that the table is to wide for the page. You need to find a way to show it in landscape format whilst leaving 
the rest of your document alone. Enter the rotating package. As before put 
\usepackage{verbatim}
in the head of your document. This allows you to rotate text, tables and figures in every manner that 
you're liable to want. To create the table use the sidewaystable instead of table. For example 
(lifted from the file rotating.tex in the package documentation).  
\begin{sidewaystable}
\centering
\begin{tabular}{|llllllllp{1in}lp{1in}|}
\hline
Context   &Length   &Breadth/   &Depth   &Profile   &Pottery   &Flint   &Animal   &Stone   &Other    &C14 Dates \\
  &         &Diameter   &        &          &          &        & 
Bones&&&\\
\hline
&&&&&&&&&&\\
\multicolumn{10}{|l}{\bf Grooved Ware}&\\
784 &---   &0.90m &0.18m &Sloping U &P1    &$\times$46  &  $\times$8  &&$\times$2 bone&  2150$\pm$ 100 BC\\
785 &---   &1.00m &0.12  &Sloping U &P2--4 &$\times$23  &  $\times$21 & Hammerstone &---&---\\
962 &---   &1.37m &0.20m &Sloping U &P5--6 &$\times$48  &  $\times$57* & ---&     ---&1990 $\pm$ 80 BC (Layer 4) 1870 $\pm$90 BC (Layer 1)\\
983 &0.83m &0.73m &0.25m &Stepped U &---   &$\times$18  &  $\times$8 & ---& Fired clay&---\\
&&&&&&&&&&\\
\multicolumn{10}{|l}{\bf Beaker}&\\
552 &---   &0.68m &0.12m &Saucer    &P7--14 &---        & --- & --- &--- &---\\
790 &---   &0.60m &0.25m &U         &P15    &$\times$12 & --- & Quartzite-lump&--- &---\\
794 &2.89m &0.75m &0.25m &Irreg.    &P16    $\times$3   & --- & --- &--- &---\\
\hline
\end{tabular}
 
\caption[Grooved Ware and Beaker Features, their Finds and
Radiocarbon Dates]{Grooved Ware and Beaker Features, their
Finds and Radiocarbon Dates; For a breakdown of the Pottery
Assemblages see Tables I and III; for
the Flints see Tables II and IV; for the
Animal Bones see Table V.}\label{rotfloat2}
\end{sidewaystable}
This method puts the table on a page on it's own. This is probably what you want if your table is that 
wide. If however you don't want it on a seperate page this can be achieved using the sideways 
and rotcaption in conjunction with the standard table command. There are some examples 
you can see for details.

There are a couple of points worth noting. The table will not appear rotated when you look at the 
resultant dvi file. You need to convert it to postscript to see it. This happens automatically when you 
print it but should you want to preview it use the command dvips -o. So for the file 
report.dvi enter dvips report -o. The other is that if you intend to print the final report 
two sided then it if you include twoside in the document class definition then the table should be 
oriented the correct way depending on whether the page is odd or even. So for example 

\documentclass[a4paper,12pt,twoside]{article}
The command sidewaysfigure works similarly. If you use the epsfig package to include eps 
files then there is another method for rotating the diagram without changing the caption. This can be 
achieved by, for example: 
\begin{figure}[hbtp]
  \begin{center}
    \epsfig{figure=test.eps, angle=67}
    \caption{Test}
    \label{fig:test}
  \end{center}
\end{figure}

Maths Tricks

If you have to type much in the way of maths it is worth investigating the AMS-LaTeX packages. 
Being designed by the American Mathematical Society they cover pretty much anything you are ever 
likely to need if it isn't provided by the standard LaTeX commands. There is very full documentation 
available in amsldoc.ps (gzipped), so I will only mention a couple of bits.

If you have tried to include text in an equation enviroment then you'll have found that the result is 
italicized and there are no spaces (unless you explicitly include them). The best way to do this is to use 
the amstext package (so \usepackage{amstext}) and then you can write 

$f(x)=\sum_{n>o}{\frac{x}{n^2}}=3 \text{ if the moon is full and } x < 5$
and other such pearls of wisdom. If you need a maths symbol and don't know it or have the manual 
handy, look at maths_guide.ps (gzipped) which includes most of them (I think).

Doing wordcounts

There is no particularly good way (that I know of) to do wordcounts of a LaTeX document. However 
within certain limits (which you'd have to be particularly abtuse to violate) the following works 
reasonably. 
detex [filename] | wc -w
And that's all folks.
                                                                                                          Ian Glover: iangl@dai.ed.ac.uk