search for: subsetbi

Hello I am trying to find a way to find the max value, for only a subset of a dataframe, depending on how the data is grouped for example, How would I find the maxmium responce, for all the GPR119a condition below: responce,mouce,condition 0.105902,KO,con 0.232018561,KO,con 0.335008375,KO,con 0.387025433,KO,GPR119a 0.576769897,KO,GPR119a 0.645120419,KO,GPR119a 0.2538608,KO,GPR119b

Hi, I'd like to select one row in a data frame per subset which is maximal for a particular value. I'm pretty close to the solution in the sense that I can easily select the maximal values per subset using "aggregate", but I can't really figure out how to select the rows in the original data frame that are associated with these maximal values. library(stats) # this