On Sep 20, 2010, at 10:28 PM, David Winsemius wrote:
On Sep 20, 2010, at 10:12 PM, Gregory Ryslik wrote:
Hi,
I have a list of 5 main elements where each main element has 247
atomic entries either 0 or 1. I need to get this into a 247x5
matrix so I do "do.call(cbind, mylist)". However, it renumbers 0
to a 1 and the 1 to a 2 so that my matrix is filled with 1's and 2's.
If I had such a problem I would see if this were more effective:
matrix(unlist(mylist), length(mylist[[1]]) )
(There is the column major order default of R matrices.)
I understand I can fix it in this case by doing a replace but I
would like to avoid that step. Further, sometimes, my list entries
will be from 0 to n. I don't want to have to always renumber all
the possibilities.
I'm not quite sure why this is going on because when I build the
following: l <- list(c(1,2,3),c(1,2,3),c(1,2,3))
and execute do.call(cbind, l) it works just fine and there is no
renumbering!
I wouldn't have expected it either, but you only provided an example
of what did work. My attempt at reproducing your problem also failed:
> ll <- list(a=c(1,0,1,1,0), b=c(0,1,0,0,1) )
> do.call(cbind, ll)
a b
[1,] 1 0
[2,] 0 1
[3,] 1 0
[4,] 1 0
[5,] 0 1
I am wondering if you are dealing with factors and have not looked
at your "list" with str(). Haven't tried my method above to see what
would happen in tat instance.
Does seem possible that is the issue:
> do.call(cbind,
list(factor(c(0,1,0,1,1,1,0)),b=factor(c(0,0,0,1,1,1,1))))
b
[1,] 1 1
[2,] 2 1
[3,] 1 1
[4,] 2 2
[5,] 2 2
[6,] 2 2
[7,] 1 2
--
David.
______________________________________________
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.
