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This page collects some examples and tips for producing a
high-quality Portable Document Format (PDF)
document that is formatted for displaying on an entire PC screen
(with something like a 4:3 aspect ratio, the most common ratio).
The obvious intent is to use the document for a PC-based
presentation (most commonly, a laptop). Since we have no
allegiance to any one O/S, we focus on software that is free and
available on the WWW for both Windows and UNIX/Linux.
With a PDF format file one can give a laptop presentation using the
Acrobat viewer.
We show a some examples written in LaTeX with a minimal number of
package-specific commands, how to prepare figures so they can be
included neatly, how to convert the LaTeX document to PDF, and
finally, how to view it.
Since PDF supports "hyperrefs" etc., you should be able to navigate by following links. If you want to get terribly fancy, you can also add a navigation panel so you can zip right to the proper slide in response to the germane question ... The different packages mentioned here have different philosophies about how much of this functionality is supported, and with what amount of difficulty.
The one we seem to use most is PDFLaTeX.
A nice set of
installation instructions and such was written by Matt Welsh.
However, we also note that Red Hat and we suspect many other standard
versions of LINUX include pdflatex as part of the standard Tex/LaTeX
distribution.
PDFLaTeX results in a high-quality pdf document that is formatted for
viewing on a PC screen or with a data projector. It directly
converts LaTeX to pdf without creating an intermediate dvi file.
The obvious intent is to use this file for giving a laptop-based seminar.
However, this strategy allows for a printed version (handouts) to be
made with minimal changes. Here are some examples written in LaTeX,
(with a few extra commands), and a description of how to prepare figures
and how to view (present) it. Finally, we note one advantage of PDFLaTeX
is that it can incorporate several types of graphics images including
jpg and png formats.
The text file example.tex is a
short example that has most of the elements that are used for
seminar overhead slides. To try this out, and transfer the files:
example.tex,
example.png,
visitus914.jpg,
gsp2.jpg,
pause.sty,
ROCK.jpg.
And then (in UNIX/LINUX):
pdflatex example
will create the file example.pdf and can be viewed by acroread (the free Acrobat reader) or the Linux viewer xpdf.
Use the /includegraphics command and refer to the
example to see how it used. It appears to be standard and more flexible
than the psfig command. Unfortunately, ps figures can not be directly
included under pdflatex, but see the conversion tips below.
Perhaps an unexpected difficulty that is encountered only
occasionally is incorporating a figure that looks "perfectly fine" when
printed or viewed in isolation but manages to become distorted when included
as part of a presentation. Incorporating figures without distorting
the graphic might mean tailoring the figure-producing package or
producing the graphic in a different format. Not all formats are supported by
the presentation software outlined here. Some packages like
PostScript (.ps), some like Encapsulated
PostScript (.eps), JPEG, etc... Most commonly,
the problem is from an overly-robust Bounding Box in the rendering package.
(It has been my experience that many packages simply "draw a big white
rectangle" and let you plot on top of that. The rectangle then dictates the
extent of the figure, even though your graphic occupies a subset of the
region. Configuring the minimally-sufficient plot region from the onset
goes a long way toward alleviating problems later.)
We recommend that one draws the figures directly in png, pdf or jpeg
format rather create later problems with the conversions from
postscript to another format.
At this point, I know of no package available for Windows and Unix/Linux that can incorporate animations/movies. Generally, I have the animation "ready" and simply minimize acroread for a moment, show the animation, and continue.
Here are some suggestions to convert postscript files or to create plots in R with the intent of including them in your talk.
convert fig1.ps fig1.pdfSometimes the ps file has too large a margin around the edges. Here is a sequence that will trim off any white space around a postscript figure. A real shrink wrap! In UNIX
ps2epsi fig1.ps fig1.eps epstopdf fig1.epsproduces the file fig1.pdf
pdf("fig3.pdf") plot( 1:10) dev.off()
png("fig3.png") plot( 1:10) dev.off()
These are great to reduce the size of images. However, typically text is not reproduced well. In UNIX use
convert -quality 100 fig1.ps fig1.jpg
A more interactive tool for conversion is xv. Setting the quality less than 100 (even just 99) will usually produce a much smaller file but with some loss of clarity. R also has a jpeg function to create jpeg figures directly.
The pdf file that is produced can be viewed easily using Abode Acrobat this is acroread in UNIX/LINUX.