on 01/20/2009 05:01 PM John Sorkin wrote: > R 2.8.1 > windows XP > > I don't understand the output from x[iS+1:iE] produced by the code below: > > x = c(1,2,3,4,5) > x > [1] 1 2 3 4 5 > > iS=2 # start position > iE=4 # end position > > [iS:iE] > [1] 2 3 4 > > # I don't understand the results of the command below. I would expect to see > 3, 4, not 3, 4, 5, NA > x[iS+1:iE] > [1] 3 4 5 NA > > Thanks, > John
Operator precedence. Note: # You are asking for indices 3:6 and of course x[6] does not exist # hence the NA # Equivalent to: iS + (1:iE) > iS + 1:iE [1] 3 4 5 6 # This is what you want > (iS + 1):iE [1] 3 4 HTH, Marc Schwartz ______________________________________________ R-help@r-project.org mailing list 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.
