1. popPCR::x_multiPop
    dPCR sample w/ >=3 populations
    json| rda| rds
    numeric
  2. popPCR::x_onePop
    dPCR sample w/ 1 population
    json| rda| rds
    numeric
  3. popPCR::x_twoPop
    dPCR sample w/ 2 populations
    json| rda| rds
    numeric