Call neuroCombat without ref_batch

[RocaVincent]

Hi,

I want to use the Python version of neuroCombat and I see that in the neuroCombat function there is an optional argument _refbatch. I understand the role of the ref batch thanks to one of the ComBat papers, but I don't understand how it can be optional since all theoretical explanations use a reference site. Can you tell me where I can find explanations about ComBat used without a reference site ?

Thanks in advance

[Jfortin1]

Hi @RocaVincent,

When no ref_batch is specified, the intercept in the model is taken as the average measurements across all sites and sites, and site/scanner effects are expressed as deviations relative to that average. When a ref_batch site is provided, site/scanner effects are expressed as deviations relative to that reference site.

[anlijuncn]

Thanks for the issue, it is really important to me

[RocaVincent]

Thanks @Jfortin1 for your quick response !