Files are in several formats which all have their advantages and
disadvantages. To save space and downloading time, they are often
For compression we use gzip version 1.2.4.
Compressed file names end in ".gz".
Here are some examples of common file formats,
illustrated in some cases with a small (two page) abstract.
HTML is used for web pages, such as this page
They can refer to files in other formats, e.g. gif (see below).
- TeX or LaTeX
source files (tex) are useful for copying text but hard to
convert to printable form unless you have the correct version of TeX or LaTeX
and the appropriate style files.
is an example written in AMS LaTeX (4203 bytes)
is the compressed version (2100 bytes).
- TeX and LaTeX produce device independent (dvi) files.
Compressed dvi files are usually small (hence fast loading) but
may give trouble with fonts. The correct fonts may need to be generated
using Metafont the first time they are needed.
Here is an example dvi file (5348 bytes)
is the compressed version (3127 bytes).
- Postscript (ps) files avoid font problems but are larger than dvi
files. If generated for a specific paper size (e.g. A4) or printer
resolution (e.g. 600 dpi) there may
be a problem printing them with a different paper size (e.g. American letter)
or printer resolution (e.g. 300 dpi).
Compression is worthwhile with postscript files.
Here is an example (67996 bytes)
and the compressed version (30132 bytes).
- Adobe Portable Document Format
is perhaps the most portable but also (usually) the largest.
You can download a free Adobe Acrobat (pdf)
(version 4.0 or higher is recommended).
Here is an example of a pdf file (89131 bytes).
For printing, the "fit to page" option is recommended.
- Some postscript and pdf files are large because they encode images
(perhaps scanned text).
- Pages which have been scanned are sometimes available in GIF (gif)
format. Here is an example (6919 bytes).
In most cases the separate gif files for each page have been combined to
give a single pdf file.
Here is a rather large example (2336671 bytes).
Other File Formats
Other formats include plain ASCII text files (txt), which are useful for
things such as numerical tables, since they can easily be used as
input to programs. Text files are often compressed.
is a plain text file (2269 bytes),
is the corresponding compressed file (663 bytes).
Here is a JPEG file (a picture, 10382 bytes).
Sometimes it is convenient to collect several files in one large
file. On Unix systems this is usually done using a TAR (tar) file.
It usually pays to compress tar files unless their
contents are already compressed.
Other systems have different utilities to accomplish the same
purpose as tar, and some combine this with compression
(e.g. PKZIP is common on DOS systems).
Here is a sample tar file (24576 bytes) and
is the corresponding compressed file (3633 bytes).
Format of Publications
In the list of
- [dvi] means a file (usually gzipped) in Tex .dvi format
(usually much smaller than postscript, but may give trouble with fonts).
- [exe] means an executable file (usually a self-extracting archive
for IBM PC or compatible computers)
- [html] means a file in hypertext markup language
- [ps] means a file (usually gzipped) in postscript format
(the page size is usually A4, but the margins should permit printing on
American letter size paper which is a little shorter and wider
- [pdf] means a file in Portable Document format.
- [tar] means a gzipped Unix tape archive (tar) format file.
- [txt] means a plain ASCII text file (possibly gzipped).
- [gif] means a gif page image (not gzipped, since gif files
are already compressed).
Viewing Compressed Postscript Files
Most of my papers are available in pdf format and/or
gzipped postscript format ([ps] above).
Most browsers can handle at least one of these formats.
For information on how to view compressed postscript on various
systems (including Windows, Macintosh, Unix), please press
Sending Files to me by Email
If you want to send me a file by email, it is reasonable to assume that
I can decode and/or print files in any of the
(there may be exceptions due to
the level, memory requirements, page sizes etc).
Plain text [txt] or
postscript [ps] is usually best.
If you send any binary files
tar, or any
they need to be encoded before being sent by email. For example, uuencoded,
"pgp -a" and "base64" encodings are acceptable.
There is no mention of Microsoft Word above.
This is because the Word format is ill-defined and proprietary.
I seldom produce Word documents and I have difficulty reading them.
If you want me to read a Word document,
please see the instructions here.
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