Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

I am building an android application that records accelerometer data during sleep, so as to analyze sleep trends and optionally wake the user near a desired time during light sleep.

I have already built the component that collects and stores data, as well as the alarm. I still need to tackle the beast of displaying sleep data in a really meaningful way, one that preferably also lends itself to analysis.

A couple of pictures say two thousand words: (I can only post one link due to low rep)

Unfiltered accelerometer activity summed @ 30 second intervals with n data points AND The same data, filtered by averaging n/100 parts

The translucent white line indicates movements that would set off the alarm, if enabled.

Unfortunately, neither of these are optimal solutions- the first is a little hard to understand for the average user, and the second, which is easier to read, hides a lot of what is really going on.

Clearly there is a better way to filter the data- I just don't have the mathematical background to know where to start looking (just look at my tags, lolz.) I'm looking for suggestions, so I can at least have some reference point to start researching a better solution.


share|improve this question
well, what do you think is your intended user supposed to see? Why would he want to see what you're showing? –  J. M. Oct 7 '10 at 16:32
Are you trying to do statistical analysis? –  KennyTM Oct 7 '10 at 18:26
@J.M. The chart are drawn in real-time as a way to convince the user that my app is actually working. After sleep has ended, the user will be able to browse their sleep movement history, which would be these time charts. As more time charts are recorded, my software will pull out some trends (still to be decided) –  Jon Oct 7 '10 at 18:27
@KennyTM I'll take a look through some questions over there- at first glance though it seems that's what I'm trying to do. –  Jon Oct 7 '10 at 18:33
Your app name is very punny. –  BBischof Oct 7 '10 at 20:07

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.