incorrect unit amplitude and location after spre.astype(recording, np.int16)

[a-zmz]

Hi,

after preprocessing with dredge motion correction, the recording data type became float32. i want to change dtype back to int16 to save some space, so i did:
int_rec = spre.astype(recording=recording, dtype=np.int16)

however, after kilosort 4 and export_report:

• in unit list.csv, all units have max_on_channel_id being imec0.ap#AP174
• amplitudes are centred at 4000
• unit location are off

unit list.csv

but before changing dtype, they look like this:

unit list.csv

could someone please help? thanks!

[samuelgarcia]

Hi.
I think you need to propagate 2 properties from the original recording after going back to int16
"gain_to_uV" and "offset_to_uV".

They must have been lost in the correct motion preprocessing step or somwhere.

The amplitude alsod epend on theses 2 factor if they are present in the recording properties

[a-zmz]

hi,

the preprocessed recording does have these two properties from the raw recording, and so does the int16 converted one.

[alejoe91]

Could this be an overflow issue? Can you try to convert to int32 instead and see how the locations look?

[zm711]

@a-zmz were you able to check it with int32 to see if it is an overflow. That is important for us to know if we need to explore this more or not :)

[a-zmz]

Hi @zm711, I was gonna do it tmr, will post the results!

[zm711]

Perfect! Thanks.

[a-zmz]

hello, i can confirm that when converting to int32, amplitude and unit locations look correct. i also tried to convert again to int16 after dtype being int32, the problem did not appear. i wonder why...