Spectral analysis. http://en.wikipedia.org/wiki/Spectral_density_estimation http://en.wikipedia.org/wiki/Spectral_density_estimation Without frequent sampling

Spectral analysis. http://en.wikipedia.org/wiki/Spectral_density_estimation http://en.wikipedia.org/wiki/Spectral_density_estimation Without frequent sampling, you can't get access to high frequency information. http://en.wikipedia.org/wiki/Nyquist_frequency http://en.wikipedia.org/wiki/Nyquist_frequency An example (not for regular sampling, but I hope it gets the point across): if a pedometer records the time of every footfall through the day, you can discern whether your pace is faster on Tuesdays than Sundays, even if you take the same number of steps. If those data are aggregated into steps/hour, you'll never see it. The lack of open access to the data acquired by a FitBit (I'd been considering buying one) is a certain dealbreaker.