This applet shows a simple pendulum that oscillates and has friction. The friction coefficient is 0.05 the initial theta is pi/3.
Hit the start button to begin the animation and graphing. Hit the Stop/Pause button to either pause the animation to to stop completely. Once paused you can renew the animation by hitting start again. You can restart the graphing at another point besides the initial theta by pausing and hitting clear. If you want to restart completely hit the Reset button.
The green line the graph shows theta vs. time. The red line shows omega vs. time.