SWIG: GIFMerge

The UA Math Department Software Interest Group (SWIG) is a self-organized informal group, consisting of faculty members, visitors, staff, and graduate students, whose goal is to promote and advance computer and software literacy among the members of the department through meetings, talks, and discussions.

Fall 2008

Mon, Sep 8, 4pm, Math 101, Remote Connection, SSH, and VNC, by Joe McMahon
Mon, Sep 15, 4pm, Math 102, An introduction to LaTeX and Beamer, by Kevin LaTourette
Mon, Oct 13, 4pm, Math 101, Paradigm Shifts in Science Based Simulations, by Mac Hyman
Mon, Oct 27, 4pm, Math 101, SQL for Joy: All your database are belong to us, by Karl Newell

For more details, and talks in past semesters, consult the full schedule of talks.

Tentative talks:

Scripting with Bash
Power Point presentation using LaTeX
GNU/Linux text editors

Interested in speaking?

Past topics can (and should) be repeated occasionally. In addition, here are some topics people might like to hear about:

Femlab (PDE modeling environment)
GAP (computer algebra software)
Getting started with Maple (or Matlab, or Mathematica, ...)
How to do math on a Mac
How to filter e-mail spam
HTML vs. XHTML (the new HTML standard)
Octave (free Matlab-like system)
PDAs (handheld personal digital assistants and much more)
PHP (server-side webpage scripting)
R (free statistics system)
Remote access (SSH, VNC, dial-up, ...)
Scientific WorkPlace (graphical front end to TeX)
Setting up a dual boot system (DOS/Linux)
TeX / LaTeX topics
Using scanners efficiently
Using the WINEDT editor (a front end to TeX, HTML)
XML (extensible markup language)
[your favorite topic here]

To give a talk, please contact swig@math.arizona.edu.

Animation created using `GIFMerge`

by Cindy Kaus

Usage

At the Unix prompt, type

gifmerge

and you will get a list of its options (below).

gifmerge [-&ltr>,&ltg>,&ltb>] [-&ltdelay>] [-l&ltloops>] [-d&ltdisp>] *.gif > anim.gif

`-&ltr>,&ltg>,&ltb>`	set transparency, ie -192,192,192; default: no transparency
`-notransp`	set transparency off (after you used -r,g,b before)
`-&ltdelay>`	set delay of between images in 1/100th secs, ie -100; default: 50 (0.5secs)
`-l&ltloops>`	set loop counter, ie -l0(ever) or -l1000, default: no loops
`-d&ltdisposal>`	set disposal 0=no action, 1= no dispose, 2=restore background, 3=restore previous, default: 2
`-pos&ltx>,&lty>`	set offset position for image
`-nopos`	reset offset position (default)

Characteristics of GIF format animation

Animation is in-line
No sound
Can control looping, background transparency, etc.
Browser specific
No controls for starting/stopping
Can be distracting
Need Netscape 2.0 or higher

Animation Examples

To generate the blinking light:
gifmerge -197,197,197 -100 -l0 perlredb.gif perlgrey.gif > perlredblink.gif
To generate the knot animation:
gifmerge -l0 -1 -0,0,0 *.gif > knotsmall.gif

Credits
To generate the animation below:
gifmerge -d0 -l0 -100 a.gif -252,243,229 -pos10,10 b.gif -pos30,30 b.gif -pos50,10 b.gif -pos70,30 b.gif > c.gif
To generate the animation below:
gifmerge -d2 -l0 -100 a.gif -252,243,229 -pos10,10 b.gif -pos40,10 b.gif -pos70,10 b.gif > c1.gif
Beginning with the following two gifs and we can get the following animation with the command:
gifmerge -d2 -l0 -50 -178,228,192 a1.gif -130,130,229 -pos10,10 b1.gif -pos40,10 b1.gif -pos70,10 b1.gif > c1.gif