Understanding Warning: Less than 20 cells found in some cell types, returning NA

[michellemeier27]

Hi,

I'm trying to understand why I keep getting this warning for my dataset when I run Cepo:
ds_res = Cepo(exprsMat = log2counts, cellType = cellType, computePvalue = 200 )
Less than 20 cells found in some cell types, returning NA

cellType %>% table() gives me:
AEC_01: 585
Epithelial_01 : 30
Fibroblast_01: 44
Fibroblast_02 : 21
LEC_01 : 1218
LEC_02 : 405
VEC_01 : 758

So I do have more than 20 cells per cell type and as I am not specifying the batch parameter it should be processing the whole dataset as one batch. Does it perform some other form of filtering where I might loose cells and leaves me with less than 20? The resulting ds_res$pvalues and all ds_res$geneStatistics are all NA, so something does go wrong. I can set the minCells parameter to fewer cells to get a result, but I would like to understand why it is failing with minCells = 20.

Thanks for your help,
Michelle