iPhone 4 fast plotting of data

I got accelerometer data coming in at 20 samples /second开发者_运维百科. I'd like to plot this data. Currently I'm using http://developer.apple.com/library/ios/#samplecode/AccelerometerGraph/Introduction/Intro.html

This works and is really fast, however I introduced a few bugs into the code that I simply cannot find!

Is there anything else that I can use for plotting data very quickly, in real time?