Subject: Re: Help with wind vector diagrams for b'fly azimuths

From: William Calvert <[email-masked]>
Date: Mon, 3 Apr 1995 12:08:48 -0500

I am conducting research on orientation of migrant monarch
butterflies. I wish to graphically represent the distribution of sited
azimuths. Does anyone know of software that could be used for this
purpose? Ideally the program would stack azimuths that were the same.
        Thanks in advance.
Bill Calvert
503 East Mary  Street
Austin TX 78704

---

From: [email-masked] (Dean Pentcheff)
Date: 5 Apr 1995 03:30:18 -0400

>purpose? Ideally the program would stack azimuths that were the same.

As you may already have found out, most graphics packages that claim to
do "polar plots" will only do a plot with 0 at the 3 o'clock position,
90 at the noon position, 180 at 9 o'clock and 270 at 6 o'clock.  Not
terribly useful for orientation data.

There are two approaches that I know of.  One is a Windows package
called Oriana.  It does a few circular statistics and some plots.  It
will stack data points when necessary.  It's commercial, so you are
entitled to official customer support.  The downside is that it costs
$125, and to be honest, doesn't seem worth it.  As far as the stats go,
it's mostly basic Rayleigh statistics.  These are easy to program (I've
got a simple command-line program that does the job.  If that's of use
to you, let me know and I'll be glad to send it to you).  The graphs
are OK, but for $125...

Anyway, it's from: Kovach computer services, 85 Nant-y-Felin,
Pentraeth, Anglesey LL75 8UY, Wales, UK.  Internet:
[email-masked].  Compuserve: 100016,2265.  They do have a
free evaluation version that you can try out for 30 days.

Another approach (as you might guess, this is what I've done) is to use
a graphics package called GLE.  It is a very nice public domain
graphics package that runs on PCs under DOS and OS/2, Unix under X
Windows, and VAXen.  It's not a "point-n-click" package, but rather you
write what amounts to a graphing program that it executes.  It produces
publication quality Postscript output, and also has drivers for HP
Laserjets and a variety of dot matrix printers.  It can be picked up
using anonymous FTP from tui.marc.cri.nz - poke around to find the
appropriate version for your platform.

It has no intrinsic polar plotting capabilities, but I've written a
macro that does it.  The nice aspect of the macro is that you can
pretty easily specify things like how many labels, whether to label in
degrees or N/S/W/E or North/South/East/West, what plotting symbol(s) to
use, and whether to draw data symbols or lines/arrows out from the
center.  "Customer support" for GLE is provided in an Internet mailing
list (to subscribe, send the following message: 
	subscribe glelist Your Name
to: [email-masked]).  I guess I'm "customer support"
for my macro...  The downside is that it doesn't stack data points -
you have to figure out what the offset from the center should be.  Hey,
you get what you pay for.

[5 hours later] OK, starting to write that got me off my duff and it
now will stack data points if that's desired.  A fairly lame
implementation of an anti-collision routine turned out to be pretty
easy to stick in.

In any case, let me know if you're interested in this stuff.  I'll
gladly send you copies of the GLE plotting routines, and source code
for the Rayleigh stats, if that's of interest.

-Dean
-- 
N. Dean Pentcheff 
Biological Sciences, Univ. of South Carolina, Columbia SC 29208 (803-777-3936)
Internet addresses: [email-masked] or [email-masked]
WWW link:  <a href="http://tbone.biol.scarolina.edu/~dean/">home page</a>