Downsample cells evenly across groups

Downsample(
  cells,
  groups,
  quality.vector = NULL,
  total.cells = NULL,
  cells.per.group = NULL
)

Arguments

cells	vector of cell barcodes
groups	vector of cell groups
quality.vector	vector of cell quality
total.cells	total number of cells to downsample to
cells.per.group	total number of cells to downsample from each group

Vector of downsampled cells