Exclude frequency range of line noise when fitting slope

[srcole]

I'm fitting a PSD (see below) for a signal after I removed line noise (data available in data.mat here). This biases the slope fit down. It might be a good idea to have a kwarg that allows the user to define frequency range(s) to ignore during the fit.

[bringingjoy]

Sub-range(s) to ignore during full model fitting are now available under the dev branch. Given the potential plural, the optional parameter expects a list of lists (and currently also works with lists of tuples).

[bringingjoy]

Dev branch is updated with the ignore_range procedure

[TomDonoghue]

Let's not close issues until they are merged to master.

This looks great, thanks @bringingjoy !

From playing with it a little:

• Right now it interpolates in linear space, which makes it curved in log space, which is perhaps not ideal since the assumption is generally that the PSD is linear in log space.
• Perhaps problematic that it uses interpolated points in slope fitting, and can fit oscillations over 'ignored' regions.

^These things might be moot (unlikely / aren't really relevant) in the use case of excluding small regions, such as line noise, but creep in more if people try to use it to exclude broader ranges, and we should be aware of implications of various ways people might use FOOOF.

I know I suggested this approach, these open issues are totally my bad.

Let me think about it a bit / play around, and see where to go from here.

[bringingjoy]

I'm sorry about closing the issue preemptively. Don't apologize - I had proposed the linear interpolation, but certainly didn't exhaust testing corner cases, so sorry for the addition of any such potential problems! It's possible that the replaced region's use during slope fitting could negatively impact the resulting fit, but cannot think of a better alternative for this presently - in many use cases, at least, it improves what would otherwise be a poor fit.

As far as fitting "oscillations" introduced by this method, we could exclude oscillations detected on the ignored interval +/- some factor of its bandwidth, or a similar constraint from being added to the overall curve.

Had another idea for accommodating slope fitting with ignoring regions, but could become much less feasible with many ranges specified, so will keep you posted if I think of anything else.