search for: cumquant

Hi, I have a data set similar to the following State Gender Quantity TX Male 1 NY Female 2 TX Male 3 NY Female 4 I need to calculate cumulative sum of the quantity by State and Gender. The expected output is State Gender Quantity CumQuantity TX Male 1 1 TX Male 3 4 NY Female 2 2 NY Female 4 6 I highly appreciate if someone can give me some hints on solving that in R. Hao -- View this message in context: http://www.nabble.com/how-to-calculate-another-vector-based-on-the-data-from-a-combination-of-two-factors-tp20532749p20532749.h...