SemiAntics

“Oh yeah! Those were big when I was little!”

~ Grace (2007 – 9 – 23)

The title of this entry is the title of a math lecture I went to a couple of years ago. It was all about these things called difference equations. They are interesting little buggers, or so they say. I haven’t studied them. The point was that there hunks of gold lying around for researchers to pick up; well, at least write papers on, since the fodder of mathematicians is published papers. To be complete, I should mention that the lecture was by Dr. Candace Kent at VCU.

I thought it was appropriate and relative to something that happened to me the other day. I know that I’m falling into the trap of the proverbial “blogger”; that is, thinking that you care what happened to me the other day. Well, assuming you do want to know, I’ll continue the story. I have a friend in the computer science department here that I had barely known for the last couple years. I still don’t really know him, but I did know that he plays guitar, so I invited him over to see if we could get along musically. It turns out that he (in my opinion) is a gifted musician with a really good grasp of theory. Most people that play guitar (and even more of those that teach themselves) never learn to read music and never learn how to make whatever chords they want just by the notes they need.

This was an exciting find for me; I never would have suspected he was such a good musician. It just goes to show what good things are lying about waiting for you to discover them.

“I must be a magician; I can turn the radio down just by giving you the evil eye!”

~ Grace (2007 – 9 – 14)

“How dare we post anything humorous on September eleventh!”

~ Grace (2007 – 9 – 13)

Not convinced? See if you can figure out where it goes wrong…

The jogl tutorial and installation instructions found on the Sun Java website are correct, but somewhat unhelpful for beginners. In particular, you need to set the CLASSPATH and LD_LIBRARY_PATH in order for the program to work correctly. Here is how I did it.

1. Make sure you have already installed the Sun version of Java.
2. Download the latest jogl files from Sun.
3. Save the file in a convenient place – I’ll assume your home directory.
4. Become superuser or root:
   $su OR $sudo su
5. Now, you need to create the directory to install it. I put it in
   /usr/lib/jogl/
6. To do that, type:
   #mkdir /usr/lib/jogl/
7. Move the zip file to that directory:
   #mv ~/jogl-<your version>.zip /usr/lib/jogl/
8. Unzip the file:
   #cd /usr/lib/jogl/jogl-<your version>/
   #unzip jogl-<your version>
9. You probably will want to change the name of the jogl directory to something like jogl-1.1.1-rc3 instead of having the architecture type on the end. (remove the -linux-i586 or whatever from the end of the name). Renaming a file is as simple as moving it from one name to the other as in “mv filename_old filename_new”.

Now you can configure the system to look there for the files when you call javac. To do this, I added the following lines to my .bashrc file:

#Add some JOGL paths - added by gnat79 on 9/9/2007
export CLASSPATH=${CLASSPATH}:/usr/lib/jogl/jogl-1.1.1-rc6/lib/jogl.jar
export CLASSPATH=${CLASSPATH}:/usr/lib/jogl/jogl-1.1.1-rc6/lib/gluegen-rt.jar
export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:/usr/lib/jogl/jogl-1.1.1-rc6/lib

The best way to do this is to use a text editor such as gedit to copy and paste it in. You may have trouble opening the file since it is hidden by default in many systems. (All files that start with a ‘.’ are hidden). You can open it with a command like this: $gedit .bashrc (from your home directory). Alternatively you can use vim to edit it. Make sure you change the version of jogl from what I have in the example.

Now you’re done!

If you see any problems with this article, please comment on it. I’m no expert! You should also read the directions that Sun has provided.