The MovingMan Java applet works pretty well, but there are still a couple of problems. There are a few things you should know:

This version of the MovingMan is written in Java 1.1.7, which is fairly new. OK, not as new as it was when I created this page. Still, if your browser is too old, it will not support this applet.

If you don't see the stick figure, his house and school, and a grid below them, press either Restart or Rescale. Either one will redraw the screen. The difference is that Restart discards all previous data and prepares for taking new data. Rescale keeps the old data and adjusts the axes to fit it. (If you don't have the Restart and Rescale buttons near the upper right corner of the window, then you don't have the applet running. Check which browser you are using, and try again with a newer browser.)

Once you get the little guy on the screen, use your mouse to drag him back and forth between his house and his school. The very first time you do this, keep him moving for a few seconds without stopping. The software is using this data to figure out how quickly your mouse will be sending data points. If you stop the guy while it is trying to figure this out, it will get confused and may not properly scale the velocity and acceleration graphs. After you have done this the first time, the speed is set until you close and restart the applet, so you don't have to worry about it.

The scaling appears to be working well on the distance and velocity graphs. That is, if you make a distance graph that includes a fairly straight line segment rising about 5 meters over the course of one second, for example, then you should see the velocity graph holding about level at a height labeled as 5 meters per second. Unfortunately, I think the scaling on the acceleration graph is not working as well. It's hard to tell, because I'm not well enough coordinated to make a straight diagonal segment in the velocity graph, but I think the acceleration shown is about double what it should be. The general shape is correct, but I think there is a bug in the method that labels the axes. I'll work on that.

If you discover any bugs, please email me and give me a description of the problem. I will try to fix it. When reporting a bug, please tell me what kind of computer you are using, what browser (including version number) and which virtual machine. Java, whose slogan is "Write once, run anywhere" could more accurately be described as "Write once, debug everywhere."

This applet was written by Lisa Denise Murphy at the University of Illinois. Early drafts were written in 1997. The current version was last revised in January of 2000. Permission is given for students and teachers to use this applet, provided acknowledgement is made of the source. Anyone interested in using this applet in connection with any published paper or commercial venture should please first consult the author. Thank you.