wx
wy
wz
running=true; //First give the variables some initial values // setballs ballx[0]=Array(-.2,0,0); ballx[1]=Array(-.2,1,0); ballx[2]=Array(-.2,-1,0); ballx[3]=Array(.6,0,0); jx=0; //Calculate the principal moments jy=0; jz=0; for(i=0;i<balls;i++){ jx+=ballx[i][1]*ballx[i][1]+ballx[i][2]*ballx[i][2]; jy+=ballx[i][0]*ballx[i][0]+ballx[i][2]*ballx[i][2]; jz+=ballx[i][0]*ballx[i][0]+ballx[i][1]*ballx[i][1]; } transform[0]=Array(1,0,0); //initialise the transform to be unit matrix transform[1]=Array(0,1,0); transform[2]=Array(0,0,1); for(i=0;i<balls;i++){ ballt[i]=ballx[i]; showball(i); }; dt = .01; //Make this smaller for better accuracy wx=5; //initial position wy=0; wz=.001; StepModel(); //Start the simulation running
dwx=(jy-jz)/jx*wy*wz; dwy=(jz-jx)/jy*wz*wx; dwz=(jx-jy)/jz*wx*wy; wx+=dwx*dt; wy+=dwy*dt; wz+=dwz*dt; omega(wx,wy,wz); //rotate and show the balls document.inputs.posx.value = wx; document.inputs.posy.value = wy; document.inputs.posz.value = wz; if(running==true){setTimeout('StepModel()',10);}
