covariates: List[str]
Additional covariates besides the batch variable such as adjustment variables or biological condition. This parameter refers to the design matrix X in Equation 2.1 in [Johnson07]_ and to the mod argument in the original combat function in the sva R package. Note that not including covariates may introduce bias or lead to the removal of biological signal in unbalanced designs.
import scanpy as sc
sc.pp.combat(adata, key="batch", covariates=None)