Hi prof!
according to
http://fem.um.es/Javadoc/OSP_EJS/org/opensourcephysics/numerics/Matrix3DTransformation.html#setOrigin%28double[]%29

i can transform a rotation about an axis of my choice say x,y,z = 0,1,0 meaning y-axis.

i added the codes

i changed i to j for the syntax creating italics in the words
for(int j=0;j<n; j++){

 rotations[j] = Matrix3DTransformation.rotationY(theta[j]);
}

the result is not what i wanted.
[img]http://www.phy.ntnu.edu.tw/ntnujava/index.php?action=dlattach;topic=2542.0;attach=4928;image[/img]
the sphere i added are rotating about it own axis, i want them rotate the coordinate system X,Y,Z


i wish to make the sphere move as if they were connected to the rectangle shapes
like in the video
http://www.nationalstemcentre.org.uk/elibrary/resource/2096/wave-machine/
[img]http://www.phy.ntnu.edu.tw/ntnujava/index.php?action=dlattach;topic=2542.0;attach=4930;image[/img]
no one seems to know as i have posted here a few days back.
http://www.compadre.org/osp/bulletinboard/TDetails.cfm?FID=59&TID=2227&ViewType=2#PID51631

any ideas?
thanks!

/htdocs/ntnujava/ejsuser/14019/users/sgeducation/lookang/WaveMachinewee_pkg/WaveMachinewee.propertiesFull screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License
Download EJS jar file(1105.8kB):double click downloaded file to run it. (2 times by 1 users) , Download EJS source View EJS source