getSingleCellExpression getSingleCellExpressionByGate maskMatrix

NumericMatrix getSingleCellExpressionByGate ( XPtr< GatingSet >  gs, string  sampleName, List  markers_pops, NumericMatrix  data, CharacterVector  markers, bool  threshold  ) assume the channel, markers are in consistent order among markers_pops, data, markers since we use numeric index to mask the columns in data matrix