[Eeglablist] Downsampling while collecting data

[Makoto Miyakoshi]

Dear Robert,

> I am considering averaging 4 samples instead because it seems like it
would reduce random noise.

Intuitively, I doubt if it works with noise under 1000/4=250 Hz. And you
need to apply antialiasing filter at or below 1000/4/2=125 Hz. So the
smoothing effect, if ever, would be negligible in the end anyway. So I'll
bet there is no difference.

Makoto

On Mon, May 16, 2016 at 3:26 PM, robert lawson <robert at sherab.net> wrote:

> I have an amp with 1000 sps sampling rate. I want to downsample to 250
> sps. The amp firmware has a filter to low pass the data before
> downsampling. I currently take every 4th sample. I am considering averaging
> 4 samples instead because it seems like it would reduce random noise. What
> are the advantages disadvantages of these 2 methods?
>
>
> _______________________________________________
> Eeglablist page: http://sccn.ucsd.edu/eeglab/eeglabmail.html
> To unsubscribe, send an empty email to
> eeglablist-unsubscribe at sccn.ucsd.edu
> For digest mode, send an email with the subject "set digest mime" to
> eeglablist-request at sccn.ucsd.edu
>



-- 
Makoto Miyakoshi
Swartz Center for Computational Neuroscience
Institute for Neural Computation, University of California San Diego
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sccn.ucsd.edu/pipermail/eeglablist/attachments/20160520/2600aac8/attachment.html>