Draft of The Internet Notebook (UNIX Review)

[rdm at cfcl.com (Rich Morin)]

.\" gt.4, 930401
.\" use troff -ms to format
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.\" Barbara-
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.\" Here is the July column.
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.\" As usual, I have copied the text to a few folks for their comments.
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.\" -Rich
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.\" P.S. to "a few folks":
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.\" This is a new draft of "The Internet Notebook" (UNIX Review) for July,
.\" 1993.  I only have ~1000 words, so please don't suggest major additions.
.\" On the other hand, please let me know if I've bozed, skipped something
.\" important, etc.	-R
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.\" Copyright 1993, Richard Morin.  All Rights Reserved.
.\"
.\" "a few folks":
.\"
.\"  geomview
.\"	geom.umn.edu:/pub/geomview
.\"	Geometry Center, software@geom.umn.edu
.\"	math/geomview
.\"
.\"  GMT
.\"	kiawe.soest.hawaii.edu:/pub/gmt		(needs netCDF)
.\"	Paul Wessel, wessel at soest.hawaii.edu
.\"	science/geog/gmt
.\"
.\"  netCDF
.\"	unidata.ucar.edu:/pub/netcdf
.\"	netcdfgroup-adm at unidata.ucar.edu
.\"	science/netcdf
.\"
.\"  gnuplot
.\"	cs.dartmouth.edu:/pub/gnuplot
.\"	David Kotz, dfk at cs.dartmouth.edu (et al)
.\"
.\"  grap (groff)
.\"	prep.ai.mit.edu:/pub/gnu
.\"	groff-1.07.tar.z
.\"	James Clark, jjc at jclark.com
.\"
.\"  GRASS
.\"	moon.cecer.army.mil:/grass
.\"	Grass Information Center, gic at zorro.cecer.army.mil
.\"	science/geog/grass
.\"	4.0 on PTF 1-2; 4.1 in beta on 930330; dox avail. for 4.2
.\"
.TL
The Internet Notebook
.br

.br
Graphing and Plotting Tools
.AU
By Richard Morin
.LP
The default UNIX plotting tools are pretty lame.
The \f(CBgraph\fP command has very limited control over data
presentation, let alone annotation.
Its companion, \f(CBplot\fP, supports a bevy of antique devices.
I can't imagine using either tool for real work.
.LP
If your UNIX vendor provides Documenter's WorkBench (DWB),
you also get \f(CBgrap\fP, a \f(CBpic\fP preprocessor for drawing graphs.
This is a real tool, but it is still severely limited.
Fortunately, the freeware community has risen to the challenge.
This column examines Geomview, GMT, Gnuplot, Grap, Graphics, and GRASS.
.SH
Geomview
.LP
Geomview is an interactive viewer for 3- and 4-D geometric objects.
Based on OOGL, an object-oriented geometry library,
it supports control panels, direct interaction, a large number of data types,
and alternative spaces (for example, hyperbolic 3-space and Euclidean 4-space).
It looks like a nifty tool for exploratory geometry and visualization.
Sadly, it only runs on SGI Irises at present.
Versions for NeXT and Sun are in the pipeline, however, so stay tuned.
.LP
Geomview can be found in \f(CB/pub/geomview\fP on \f(CBgeom.umn.edu\fP.
For more information on the package,
contact the Geometry Center of the University of Minnesota
(\f(CBsoftware@geom.umn.edu\fP).
.SH
Generic Mapping Tools (GMT)
.LP
GMT is a very powerful batch-mode plotting package,
with particular strengths in geographic applications.
Its design borrows heavily from UNIX notions,
and should seem familiar to UNIX-oriented scientists and programmers.
.LP
Small, specialized programs are used in combination
to produce arbitrarily complex results.
The programs (over 50 at this count) are written in C,
and are normally used by means of shell scripts.
For convenience, all GMT programs read default parameter settings
from a ``defaults'' file, located in the current (or home) directory.
They also ``remember'' parameters given in previous invocations.
A shorthand syntax can be used to ``recall'' these in subsequent calls.
.LP
Most input and intermediate data are kept in ASCII form,
for portability and readability.
(2-D gridded data sets are kept in NCAR's binary netCDF format.)
Graphical output files are written in PostScript,
allowing a wide range of display devices.
.LP
The GMT-SYSTEM, distributed as seven megabytes of compressed archives,
can be found in \f(CB/pub/gmt\fP on \f(CBkiawe.soest.hawaii.edu\fP.
The software comes with a license agreement,
designed for use by non-profit educational/research institutions
and U.S. Government agencies.
Other parties should contact Paul Wessel (\f(CBwessel at soest.hawaii.edu\fP).
The Unidata network Common Data Form (netCDF) software can be found in
\f(CB/pub/netcdf\fP on \f(CBunidata.ucar.edu\fP.
.SH
Gnuplot
.LP
Gnuplot is a command-driven interactive function plotting program.
Surprisingly, it is \fInot\fP a product of the GNU Project,
just a happy coincidence in the freeware name space.
This C program accepts function descriptions in a superset of C syntax.
It provides a variety of scaling and labeling options,
and supports dozens of output devices.
.LP
Gnuplot is archived in \f(CB/pub/gnuplot\fP on \f(CBcs.dartmouth.edu\fP.
Many authors have worked on Gnuplot,
and it is still supported by an active community.
To join the Gnuplot mailing list,
send a note to \f(CBinfo-gnuplot-request at ames.arc.nasa.gov\fP.
.SH
Grap (and Groff)
.LP
If your vendor \fIdoesn't\fP provide DWB II,
or a reasonable facsimile thereof,
you may still be in luck.
Groff, by James Clark,
is a complete freeware reimplementation of the UNIX \f(CBtroff\fP suite.
Unfortunately, it's a trifle demanding to assemble.
.LP
Groff itself is archived as \fBgroff-*.tar.z\fP
in \f(CB/pub/gnu\fP on \f(CBprep.ai.mit.edu\fP.
To build it, however, you will need a C++ compiler.
The same directory holds \fBgcc-*.tar.z\fP,
as well as \fBgdb-*.tar.z\fP, the GNU debugger.
The three packages add up to a bit over ten megabytes, compressed.
.LP
Once you have them, build Gcc, then Groff,
and you should be on your way.
Don't forget to send off a check to the Free Software Foundation
(\f(CBgnu at prep.ai.mit\fP), who brings you these fine programs.
.SH
GRASS
.LP
The Geographic Resources Analysis Support System (GRASS)
combines a raster geographical information system (GIS),
a vector GIS,
an image processing system,
and a graphics production system.
Consequently, it is fairly large;
the compressed archives take up more than 15 MB.
.LP
With nearly 200 programs and 300,000 lines of code,
GRASS is not a system to approach casually.
It requires a substantial investment of time,
but repays this with a broad range of capabilities.
It isn't for everyone, but any individual or institution
who is interested in large-scale analysis of data should
give GRASS a serious look.
.LP
More generally, GRASS is an excellent (award-winning!) example
of properly handled government freeware.
The software is developed by and for the government,
with coordination provided by an inter-agency steering committee.
GRASS is very actively supported, with annual user meetings, classes,
distribution centers, educational materials, email lists, a newsletter,
and videotapes.
.LP
GRASS has a diverse user community.
Federal agencies account for 40% of the users.
Private firms and educational institutions each take up another 25%.
The remaining 10% is split among domestic and foreign governmental bodies.
GRASS is in the public domain; public distribution and use is encouraged.
The official GRASS archive is \f(CB/grass\fP on
\f(CBmoon.cecer.army.mil\fP.
Contact the Grass Information Center
(\f(CBgic at zorro.cecer.army.mil\fP or 
+1 800-872-2375x220) for more information.