Detect badly scaled plots in raw.plot, warn and propose auto-scale

[mscheltienne]

Again on the forum: https://mne.discourse.group/t/raw-plot-shows-an-empty-figure/10371
This kind of scaling problem is common, I remember seeing it several times on the forum. How about we:

• detect data which is likely badly scaled when calling raw.plot()
• issue a warning as a pop-up window
• propose in this pop-up window to auto-scale the data

At least on the Qt backend.

[larsoner]

Agreed this is probably most easily doable in the Qt backend. +1 for moving it to mne-qt-browser and someone can implement it when they have time!

It would also be good to be able to disable this pop-up window using an MNE-Python config var, as I could see how for some workflows people might know their data scales yield huge traces and it would be bad if they always got an unnecessary popup.

[drammock]

I hesitate a lot about adding pop-ups like this. Is a (big, bold, all-caps?) warning in the terminal not sufficient?

[mscheltienne]

I hesitate a lot about adding pop-ups like this. Is a (big, bold, all-caps?) warning in the terminal not sufficient?

In my experience, people easily miss it when they have a GUI open, usually in front of the terminal.
Another option would be a small part of the GUI dedicated to 'logs' which would forward info levels logs in white, warning in red, ...

[drammock]

In my experience, people easily miss it when they have a GUI open, usually in front of the terminal. Another option would be a small part of the GUI dedicated to 'logs' which would forward info levels logs in white, warning in red

Fair enough. +1 then for @larsoner's suggestion:

It would also be good to be able to disable this pop-up window using an MNE-Python config var