Takes an average, potentially on a different scale given by fun.natural
of some genes. The average is then transformed with fun.cycle.
primerAverage(fd, geneGroups, fun.natural = expavg, fun.cycle = logshift)
SingleCellAssay or subclasscharacter naming a column in the featureData that keys the duplicatesaveraged version of fd.
This code needs to be tested more extensively after a refactoring. Caveat calculator.