Please I need some help using R to analyze my data. What I would like to do is to repeat the same basic process (e.g. linear regression between wood density and distance from pith) for at least 240 data subsets within the main data-frame. Within the main data-frame, these data subsets will be defined by three variables namely, Â species, individual and core (i.e. 20 species, at least 6 individuals of each species, and 2 cores from each individual). Â Whereas I can write the code to carry out this process for each subset, I am unable to successfully instruct R to automatically carry out the process for each of these subsets (perhaps using loops). So to illustrate what I have done so far with the codes below I was able to run a regression analysis for core âaâ of individual 1 in the species âApeimeâ. But rather than do this 240 times, I would like to tell R to repeat the process automatically using loops or any method that works.
 Code:  RG2<-BCI[BCI$Species == "APEIME" & BCI$Individual == 1 & BCI$Core == "a", ] > plot(x=RG2$DP..cm., y=RG2$WD..g.cm3, xlab="Distance from pith cm", main="APEIME1a", ylab="Wood density g/cm3") > RG2lm<-lm(RG2$WD..g.cm3~RG2$DP..cm.) > summary(RG2lm)  Thanks  Oyomoare [[alternative HTML version deleted]]
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