Re: [R] Selecting elements from a vector (a simple question with weird results)

2009-03-29 Thread andrew
aa[order(aa)] is the same as sort, although sort is much quicker and has lower memory requirements: > aa <- rnorm(1000) > all(aa[order(aa)] == sort(aa)) [1] TRUE > system.time(sort(aa)) user system elapsed 7.270.088.25 > system.time(aa[order(aa)]) user system elapsed 29.58

Re: [R] Selecting elements from a vector (a simple question with weird results)

2009-03-28 Thread Tal Galili
Yes Johannes - That helped, thank you. On Sat, Mar 28, 2009 at 11:50 PM, Johannes Huesing wrote: > Tal Galili [Sat, Mar 28, 2009 at 06:48:36PM CET]: > > Hello people. > > > > I wish to reorder a simple vector of numbers by another vector of the > order > > (and then do the same, but with a da

Re: [R] Selecting elements from a vector (a simple question with weird results)

2009-03-28 Thread Johannes Huesing
Tal Galili [Sat, Mar 28, 2009 at 06:48:36PM CET]: > Hello people. > > I wish to reorder a simple vector of numbers by another vector of the order > (and then do the same, but with a data frame rows) > > I try this (which doesn't work) : > > aa <- c(3, 1 ,2 ) > > aa[aa] > [1] 2 3 1 To my mind, i

Re: [R] Selecting elements from a vector (a simple question with weird results)

2009-03-28 Thread Tal Galili
Thanks Jorge , I mistakingly (and foolishly) confused a vector of ranking, to a vector of ordering that ranked vector... Patrick Burns explained to me that I was looking for: aa[order(aa)] df[order(df[,1]), ] Sorry, Tal On Sat, Mar 28, 2009 at 9:08 PM, Jorge Ivan Velez wrote: > > Dear Tal,

Re: [R] Selecting elements from a vector (a simple question with weird results)

2009-03-28 Thread Jorge Ivan Velez
Dear Tal, It works as it should. In this code: # Data aa <- c(3, 1 ,2 ) aa [1] 3 1 2 aa[aa] [1] 2 3 1 you are telling R to do the following: take the vector aa and select the elements aa (in R language that is aa[aa]). If you look carefully, the third element of aa is 2, the first is 3 and the

Re: [R] Selecting elements from a vector (a simple question with weird results)

2009-03-28 Thread Tal Galili
Thanks Patrick, Sorry to have missed that! Tal On Sat, Mar 28, 2009 at 9:01 PM, Patrick Burns wrote: > I presume you are looking for: > > aa[order(aa)] > > and > > df[order(df[,1]), ] > > > Patrick Burns > patr...@burns-stat.com > +44 (0)20 8525 0696 > http://www.burns-stat.com > (home of

Re: [R] Selecting elements from a vector (a simple question with weird results)

2009-03-28 Thread Philipp Pagel
> I wish to reorder a simple vector of numbers by another vector of the order > (and then do the same, but with a data frame rows) > > I try this (which doesn't work) : > > aa <- c(3, 1 ,2 ) > > aa[aa] > [1] 2 3 1 > > The same won't work if I try to order a data frame: > > data.frame(matrix(c(3,1