search for: contions

Hi netters, Suppose I have two data frames X and Y. X has three colnames A, B and C. Y has three colnames A,B and D. I want to combine them into one matrix, joining the rows having the same A and B values (X$A==Y$A and X$B = Y$B). So the resulting dataframe has four variables/columns: A,B,C and D. I was wondering what's the best way to do it in R. Could anyone give me some advice? Thanks!

Hi All, I'm having trouble selecting rows to delete, that i can't seem to overcome. Below is some sample data, i am trying to dedup the data based on each user, and simultaneously the timestamp (at the side i have highlighted expected row to be removed) I've looked at the lag function but can't seem to make it work? My logic ran along the lines of an ifelse statement and then

Hi All, I am using canonical correspondence analysis to compare a community composition matrix to a matrix of sample spatial relationships and environmental variables. In order to parse out how much variance is explained purely by space (S/E) or the environment (E/S) I am using a conditional (partial) CCA. I want to test significance via Monte Carlo but I can not find a way to do this with a