Tweet
I am analyzing the walking patterns of rats before and after spinal cord
injuries. I am employing standard 60 hz video technology and have run
into some significant concerns. Visual inspection of the vertical
coordinate data reveals a time series resembling a textbook illustration
of aliasing error. The possibility of aliasing seems reinforced by the
difficulty I am faving in selecting an appropriate filtering algorithm -
nothing seems to work well and I have more confidence in the raw data
than in the filtered data. Part of the smoothing difficulty may be
attributable to the relatively small number of points in eac time series
(14-17 points per stride). In any case, the problems all seem to point
toward sampling rate and the frequency content of rat walking. Any
information you could provide regarding the frequency content of rat
walking, sampling rate, and appropriate filtering algorthims would be
greatly appreciated.
Thank you,
William (Bill) Siler, Ph.D.
Saint Louis University
silerwl@slu.edu
injuries. I am employing standard 60 hz video technology and have run
into some significant concerns. Visual inspection of the vertical
coordinate data reveals a time series resembling a textbook illustration
of aliasing error. The possibility of aliasing seems reinforced by the
difficulty I am faving in selecting an appropriate filtering algorithm -
nothing seems to work well and I have more confidence in the raw data
than in the filtered data. Part of the smoothing difficulty may be
attributable to the relatively small number of points in eac time series
(14-17 points per stride). In any case, the problems all seem to point
toward sampling rate and the frequency content of rat walking. Any
information you could provide regarding the frequency content of rat
walking, sampling rate, and appropriate filtering algorthims would be
greatly appreciated.
Thank you,
William (Bill) Siler, Ph.D.
Saint Louis University
silerwl@slu.edu