search for: indiviadual

Hi everyone, I have been working some days in a nested loop in R but I can't find the solution. I have a data.frame with an unique ID for individuals and unique ID for different stands, for each indiviadual I have a dbh record and a SBA (stand basal area) field. Pma<-rep (1:40) P<-seq(1,4, 1) Plot<-rep(P,10) dbh2<-rnorm(40, mean=200, sd=5) SBA2<-rnorm(40, mean=10, sd=1) As I want to calculate the basal area of larger trees in each stand (i.e., the compare tree to tree the dbh and for...