extract umi matrix for the genes in the set, possibly donwsampling

gset_get_feat_mat(
  gset_id,
  mat_id,
  downsamp = F,
  add_non_dsamp = F,
  downsample_n = NA,
  gene_names_src_targ = NULL
)

Arguments

gset_id: gene set in scdb
mat_id: mat in scdb
downsamp: if this is true the returned matrix is downsampled
downsample_n: number of umis for downsampling (if this is NA, the system will pick up the default heuristic)
gene_names_src_targ: string pair, defining how to convert gene nmaes from the original matrix to the naming scheme of the returned matrix (NA by default, in which case no conversion will be done)
add_non+dsamp: should cells with fewer umis than the downsampling threshold be added to hte matrix with their raw data