Where can I get details of the anti-aliasing filter applied before resample

Support & Discussions
1

In the documentation of raw.resample it says

If appropriate, an anti-aliasing filter is applied before resampling. See resampling-and-decimating for more information.

Upon further inspection, I can’t seem to find the piece of code in BaseRaw.resample that actually applies any LP/AA filter. Where is this actually happening?
Where can I find information about the filtering applied (a reviewer requested it)?

  • MNE version: 1.3.1
  • operating system: Kubuntu 22.10
2

@skjerns Hi,

Have a look here. Hope this can answer your query:

https://mne.tools/stable/auto_tutorials/preprocessing/25_background_filtering.html

https://mne.tools/stable/auto_tutorials/preprocessing/30_filtering_resampling.html

best,

3

Not really, to me it is not clear which of these settings is now used.

In the docstrings it says

This built-in filtering that happens when using raw.resample(), epochs.resample(), or evoked.resample() is a brick-wall filter applied in the frequency domain at the Nyquist frequency of the desired new sampling rate.

However, I find it difficult to understand what the parameters of the brick-wall filter are. Or are they parameterless? Unfortunately, in the code itself it does not become apparent what the settings are or what I should report.