if(0%in%colSums(counts)){Error="At least one of the column of the counts table is 0"}
if(min(counts)<0){Error="The counts table must contain only positive values"}
if(MGSTable&&length(which(toupper(colnames(counts))%in%"SIZE"))!=1){Error="The counts table must contain a column named SIZE providing the length of each gene"}
}
}
if(TRUE%in%sapply(counts,is.na)&&is.null(Error)){Warning="NA values are considered as 0 is the counts table";counts[sapply(counts,is.na)]=0}
if(nb==1&&level=="NA"){Error="At least one column contains only NA"}
}
if(MGSTable&&length(which(toupper(colnames(taxo))%in%"MGS"))!=1){Error="The taxonomy table must contain a column named MGS providing the MGS association of each gene"}