Powerpoint Me in the Other Direction

Some alternative methods for Linux users to create presentations

Michael J. Jordan, Linux Online Staff

April 20, 2007

I don't often use presentation creation software in office suites. Since I avoid Microsoft products, I have never used Powerpoint. Owing to its popularity, however, it has inspired similar offerings that run on Linux - namely, OpenOffice Impress and KPresenter, part of the KOffice suite. I have used these on some occasions, but I have never quite warmed to them. The are fine pieces of software and the developers should be given their fair share of praise, but they don't really fit into my style of work.

And what is that style? Well, first of all, I like getting my hands dirty. I prefer working with text files to using 'What You See Is What You (sometimes) Get' programs. I don't like being in a working environment that says to you: 'If it's not in the menu options, then you can't do it'. I like to give my creativity free reign.

In this article, I'll talk about two ways in which I create presentations. One is using a tool kit called Beamer, which is part of the typesetting system LaTeX. If you're familiar with LaTeX, then you've already got a head start. If not, I'll give you short intro on LaTeX - just enough to get you started - and then we'll just right into using Beamer.

The other is my own home-brew solution to presentation. This has allowed me to overcome the limitations I find when using the mainstream presentation software tools, while also producing portable and (I hope) attractive presentations.

Latex Beamer

This Beamer doesn't have anything to do with the BWM, but you can use it to make luxurious presentations. To use it, you need to have the the LaTeX tools. If you haven't already got it, its best to install the latest version of a package called 'Tetex'. This should include Beamer, though it was my experience with Ubuntu Edgy (the latest version is Feisty at the time of this writing), that I had to install a separate package called 'latex-beamer'. At any rate, with either or both of these packages installed, you're ready to start out creating presentations with Beamer.

What Is Your Area of Expertise?

Whatever your area of expertise, Beamer is a great tool to get your thoughts up on the big (or small) screen and out to your audience. In my case, I was trained as a foreign language teacher, a profession with which I am still involved. Specifically, I teach English to speakers of Spanish. So the example that I have prepared here is presentation that I will be using in one of my classes.

Let's get started

First, we'll create a template which you'll be able to use as a starting point for future Beamer presentations. Here's what we need to start:

%% Template for Beamer Presentations

\documentclass{beamer}

\mode

%% define the look and feel
\usetheme{Boadilla}
\useinnertheme{rectangles}
%\usefonttheme{structurebold}
\usecolortheme{orchid}
%\useoutertheme{tree}

\title{An English Lesson}
\institute{Lexica Language Institute}
%% the following date format removes the date
\date{}

%% puts the LLI logo at the bottom right
\pgfdeclaremask{lli}{lli_logo}
\pgfdeclareimage[mask=lli,width=0.5cm]{lli-logo}{lli_logo}
\logo{\vbox{\vskip0.1cm\hbox{\pgfuseimage{lli-logo}}}}

% declare lesson images %
\pgfdeclareimage[interpolate=true,width=3.0cm,height=2.5cm]{tortilla-bw}{tortilla_bw}
\pgfdeclareimage[interpolate=true,width=3.0cm,height=2.5cm]{tortilla-color}{tortilla_color}


\begin{document}
\begin{frame}
\titlepage
\end{frame}
\section*{Outline}
\begin{frame}
\tableofcontents
\end{frame}



\end{document}

Let's explain this step by step. First, we need to tell LaTeX what kind of a document this is. LaTeX is sort of a cross between a document format and a programming language. We actually need to 'compile' the document before we can read it. In the first two lines, we're basically telling the LaTeX compiler to use the Beamer document types and to format it in presentation mode.

I should point out here, in case you're wondering - that anything with a percent sign (%) in front of it is a comment for the author's use only and will not appear in the document.

Next, we tell LaTeX how we want our document to look. The first option we've defined is to use the theme 'Boadilla' included with Beamer. Of all the themes Beamer has to offer, this to me is the nicest. Seeing that this is my opinion, however, it's best to check them all out for yourself. If you go to the directory /usr/share/texmf/tex/latex/beamer (on most Linux systems, though your mileage may vary), you'll find all of the files related to the look and feel of your presentations. Most of the main themes have the names of major cities. When you complete your first draft, just substitute different names and recompile until you see one you like. The next option, \useinnertheme{} will change the look of the bullet points on your outline page. Here, I have used rectangles but you can also use circles. Speaking of the outline, if you want to have the contents in bold text, just use the option \usefonttheme{structurebold}, which I have commented out. The next option, \usecolortheme, does just what it says. It declares the main color for your presentation. As with the main themes, you can see the different color options at /usr/share/texmf/tex/latex/beamer/. They have names like 'beetle', 'albatross' and 'whale'. Try different ones until you find one that suit your needs.

The next step is to declare the title of our presentation. Following, there is a declaration for \institute. I am assuming that this comes from the fact that Beamer was designed for academic presentations. Here, you can put the organization that you work for. Following this declaration, you'll see that we have a comment about the date. By default, Beamer will include the date when you created the presentation on the front page. If you don't the date to appear, you simply put the date declaration here with empty brackets. This is good if you're going tor re-use the presentation over and over again. Alternatively, you can add a fixed date in the brackets and regardless of whether you compile it a dozen times after, it will always show the same date.

Below the date declaration, we're going to add some code to include our organization's logo to the lower right corner of each page. The first time I did this, I found it a bit tricky, so here are some tips that should make this a bit easier. First, try to make your logo as big as possible and then convert it to PDF format. I find that this is the format that works best. Then, as you'll notice above, I have differentiated the declaration of the logo for the document and the actual file name by using a hyphen (-) in the former and an underscore (_) in the latter. That is to say, when I created the file I called it 'lli_logo.pdf' and when I declared it just below in the logo declaration, I called it 'lli-logo'. For a good example to show you the size of the image you'll need for a logo, have a look at /usr/share/texmf/tex/latex/beamer/beamericonarticle.pdf

Related to the logo declaration, if we want to use any images in our presentation, here is the place to declare them as well. In this case, I used normal sized JPG images. You'll need to reduced actual sizes of the images, so you can see we declare the width and height here in centimeter values. When you actually place the images in the presentation, you'll need to use the \pgfuseimage{} declaration. More on that shortly.

The next series of declarations are needed for every Beamer presentation. Below the self-explanatory \begin{document} is the code we need to produce the page with our outline. When we have these series of declarations in our document, we're ready to start creating our content.

Each page of a beamer presentation, called a 'section', is comprised of a 'frame' where we have our content. Inside each frame, we'll be writing our content and controlling its format with the LaTeX language. It is actually much easier than it seems. Once we have one presentation under our belt, we can use it to create other ones. We'll be just plugging in the LaTeX code around our content (or inserting our content into LaTeX code - however you want to look at it).

Providing your Content

Here's the first section, or page of our presentation inside our first 'frame'.

\section{Our English Lesson  - Intro}
\frame
{
\begin{block}{Our English Lesson - Intro}
Here, we'll make some introductory remarks about our lesson. \\
%% reveal next line
\pause
\vspace{3mm}
\textit{\textbf{Let's go! }}\\
\end{block}
}

First, we use the \section declaration and place the section title in the brackets. Since my presentations have one frame per section, I use the same title in the frame, as you can see in this example. From here on, this is where your content goes. It's placed in brackets which start after the \frame declaration. Notice also that when you want a line break, you need to add two slashes (\\). On the next line, you'll see a \pause declaration. This will make sure that your next line is invisible until you press the 'next page' button on your final presentation. If you want some space between lines, just add a \vspace{} and a value in the brackets. I find somewhere between 1.5mm to 3mm to be sufficient. This depends on how much content you want to fit on the page. The line 'Let's Go!' will appear in bold and italics.

Now, if you're not familiar with LaTeX formatting, it may seem a bit complicated to achieve this. You're probably thinking that Powerpoint or OpenOffice presentation software is much friendlier. Well, in a certain way, they might be. But in Linux, there are special LaTeX editors that will let you do the LaTeX formatting much more easily than it may appear at first. An editor called Kile will help you with that. Personally, I use Emacs and with a couple of mouse clicks, you can change the formatting as if it were a normal word processor. I have never had any difficulty with it. There is also a WYSIWYG-style LaTeX editor called LyX. Though I have used it to create 'normal' documents, like a word processor, I don't use it for producing Beamer presentations. There are, however, Beamer templates available for LyX.

Regardless of the editor that you choose to create your content, you can add a lot of eye candy to your Beamer presentation with very little effort. For example, let's say we want to create a table with some data. First, you may want to center it on the page. Here's how you would do that in latex:

\begin{center}
Irregular Verbs in English\\

Then, we would add the 'tabular' declaration and some parameters.

\begin{center}
Irregular Verbs in English\\
\vspace{2mm}
\begin{tabular}{|l|l|}

Let's explain what we've done here. After our tabular declaration, we have to configure the layout and look of the table. We've done this here with {|l|l|}. The pipe (|) character means that we should have vertical lines between cells. For example, if we didn't want any lines on the outsides of the table, we would use this: {l|l}. The letter 'l' means that the contents of the cells should be adjusted to the left. That is, a centered cell would be {c|c} and if we wanted it to the right, it would be {r|r}. All of these examples contain two columns. If we wanted more, we would just increase the number of 'l', 'c', or 'r's. This would be five columns, with vertical lines throughout the table, adjusted to the left: {|l|l|l|l|l|}

Now, we need to add the data to the table:

\begin{center}
Irregular Verbs in English\\
\vspace{2mm}
\begin{tabular}{|l|l|}
\hline
\textbf{English}&\textbf{Spanish}\\
\hline
be&ser/estar\\
come&venir\\
drink&beber\\
drive&conducir\\
\hline

As you can see, the content of the cells need to be separated by the ampersand (&). The end of the row is marked by two slashes (\\). In this example, I have separated the heading of the table from the content with \hline, which draws a horizontal line. I have done the same after the last row of the table. Now, we just need to close our table.

\begin{center}
Irregular Verbs in English\\
\vspace{2mm}
\begin{tabular}{|l|l|}
\hline
\textbf{English}&\textbf{Spanish}\\
\hline
be&ser/estar\\
come&venir\\
drink&beber\\
drive&conducir\\
\hline
\end{tabular}
\end{center}

To me, though, there's something bland about this table. It might be a good idea to spruce things up. Let's add a little color. To do this, we'll need to go back to the beginning of our document and add this: \usepackage{colortbl}. Just put this line in the look and feel section. Now we'll be change the colors of our table.

\begin{center}
Irregular Verbs in English\\
\vspace{2mm}
\begin{tabular}{|l|l|}
\hline
\rowcolor{red}\textbf{English}&\textbf{Spanish}\\
\hline
be&ser/estar\\
come&venir\\
drink&beber\\
drive&conducir\\
\hline
\end{tabular}
\end{center}

As you can see, by placing \rowcolor{some color} before the row in the table, the background of these cells changes to the color you specified. Of course, you can also apply these tricks to individual words. For example, you can highlight a word in red by doing this:

\textcolor{blue}{English}

And you're not limited to only the colors that LaTeX supports. You can also use the HTML color values to get more exotic colors:

\textcolor[HTML]{990000}{Spanish}

You can also use the HTML values to change the row colors:

\rowcolor[HTML]{ccccdd}\textbf{English}&\textbf{Spanish}\\

For the final touch, we need to put the images that we declared at the beginning into a page of our presentation. This is pretty easy. Here's all you need to do:

\section{!`Una tortilla muy rica!}
\frame
{
\begin{block}{!`Una tortilla muy rica!}
\begin{center}
\pgfuseimage{tortilla-bw}\\
Una tortilla\\
\vspace{2mm}
\pause
\pgfuseimage{tortilla-color}\\
!`Una tortilla muy rica!
\end{center}
\end{block}
}

Simply use the \pgfuseimage{your-image} with the name you declared at the beginning. Here, I created an effect of having a boring black and white image and contrasting it with the same image in color with a pause in between.

Now, to create the final presentation, which will be in PDF format, just type the command: pdflatex. Assuming you didn't get any errors, you should be able to see it with any PDF viewer. Since Adobe Acrobat Reader is available on all the major platforms, you can just load your presentation on a pen drive and take it with you to that next big conference. I also must say that I really like the look of a Beamer presentation. There is a professional look about it. I think your audience will find it appealing.

Here's the full source code and the finished PDF.

Of course, there is a lot more you can do to change the look of your Beamer presentation. I have just given you a brief introductory on how to get started. But, even with this quick look, I think you'll see why Beamer is an excellent tool for getting your ideas across in presentation form.

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