Issue with filter_ripple_band padlen

[m-zimmerman]

Hello,

I wanted to try playing around with my own LFP ephys recordings, but cannot seem to run my lfps array (shape=(7350,)) with the filter_ripple_band(lfps) function to get the filtered_lfps.

The ValueError I get is "The length of the input vector x must be greater than padlen, which is 954." which is traced back to the "filtered_data[~is_nan] = filtfilt(filter_numerator, filter_denominator, data[~is_nan], axis=0)" section of the code.

Let me know if you have any ideas or need any more information!

[edeno]

Three things to note here:

1. The ripple filter here is designed for a signal sampled at 1500 Hz. If your signal is not this, then I would recommend constructing your own ripple filter.
2. I believe this function is expecting something of shape (7350,1) because it is built to process multiple LFPs.
3. The other possibility is that you have a bunch of NaNs in your input data.

[m-zimmerman]

Thanks for the quick reply!

Your second point answered the issue. I needed the extra dimension for the functions to work (I thought I saw in the code it was commented to be shape (X,) ).

Also, to your first point, am I correct in assuming this filter_ripple_band() function is essentially applying a bandpass filter in the high gamma range on the lfp signal?

Appreciate the help!

[edeno]

Correct. The filter is for 150-250 Hz. I'm going to close this issue, but feel free to open it back up if there is an issue.