On Mon, 28 Jan 2008, Waverley wrote: > I have a data vector as following: > > z > [1] 183.1370 201.9610 113.7250 140.7840 156.2750 42.1569 42.1569 42.1569 > [9] 240.1960 308.4310 42.1569 42.1569 42.1569 42.1569 42.1569 42.1569 > [17] 42.1569 42.1569 42.1569 42.1569 279.8040 42.1569 42.1569 > > when I sort, it gave me the right order > > > sort(z) > [1] 42.1569 42.1569 42.1569 42.1569 42.1569 42.1569 42.1569 42.1569 > [9] 42.1569 42.1569 42.1569 42.1569 42.1569 42.1569 42.1569 113.7250 > [17] 140.7840 156.2750 183.1370 201.9610 240.1960 279.8040 308.4310 > > BUT when I use the order, the returned index is strange and not right. > You can check the first 4 values. > > order (z) > [1] 6 7 8 11 12 13 14 15 16 17 18 19 20 22 23 3 4 5 1 2 9 21 10
Seems ok to me. Maybe you are looking for rank()? Order gives the ordering permutation, rank the inverse, i.e.: R> z2 <- sort(z) R> identical(z2, z[order(z)]) [1] TRUE R> identical(z, z2[rank(z)]) [1] TRUE hth, Z > I am not sure why R does not order it correctly when handling a vector > with repetitive values. > > I use just the first 4 values of z, then it ordered correctly. > > order (z[1:4]) > [1] 3 4 1 2 > > Can someone help? What is the problem here? Is this a R bug? How to > order when handling a vector with repetitive values? > > -- > Waverley @ Palo Alto > > ______________________________________________ > 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. > > ______________________________________________ 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.
