Consider a data frame named data. data contains 4 columns and 1000 rows. Say the aim is to bring together columns 1, 2, and 4, if the values in column 4 is equal to 1. We could use the syntax
data(data[,4] == 1, c(1 2 4)) for this purpose. Suppose now that the aim is to bring together columns 1, 2, and 4, if the values in column 4 is equal to 1, for the first 20 rows of column 4. We could use the syntax data(data[1:20,4] == 1, c(1 2 4)) for this purpose. However, this does not produce the desired result. This is surprising at least for someone coming from MATLAB because MATLAB produces what is desired. Question 1: The code makes sense but why does it not produce what we expect it to produce? Question 2: What code is instead suitable? ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
