>
> A potential problem with this way of filtering epochs is that the filter
> concatenates the epochs together and treats each channel like a continuous
> signal. Due to the filter impulse response, this will lead to the
> propagation of information from one epoch (sample) to the next (but this
> also happens when you filter Raw) and can cause artifacts when there are
> discontinuities between the epochs. These problems could be avoided by
> using short FIR filters and applying them independently for each epoch..
> but this will limit the frequency response of the filters we can support.
> An advantage would be that it would also work for the real-time epochs and
> the result would not depend on the order of the epochs.
>
> @agramfort <https://github.com/agramfort> @Eric89GXL<https://github.com/Eric89GXL>thoughts?
>

indeed it's a bad idea to filter after epoching unless you use a very short
FIR filter
such as a savitzky-golay filter, which should not be a priority. The
filtering should
happen in the server side or RtClient.