Jim,
Thank you for your help. I had a feeling it would be an apply function
that could help.
Kind regards,
Greg
jim holtman wrote:
Your example has one more element in 'ind' than 'example' and that is
what causes the error, but this should be close.
> #sample data
> set.seed(100)
> example = list(letters[1:10], letters[1:10], letters[1:10])
> ind = list(as.logical(sample(0:1, 10, rep=TRUE)),
+ as.logical(sample(0:1, 10, rep=TRUE)),
+ as.logical(sample(0:1, 10, rep=TRUE)),
+ as.logical(sample(0:1, 10, rep=TRUE)))
>
> mapply(function(a,b)a[b], example, ind)
[[1]]
[1] "c" "g" "i"
[[2]]
[1] "a" "b" "e" "f" "j"
[[3]]
[1] "a" "b" "c" "d" "g" "h" "i"
[[4]]
[1] "b" "d" "e" "f" "h" "i"
Warning message:
In mapply(function(a, b) a[b], example, ind) :
longer argument not a multiple of length of shorter
>
On Fri, Jun 26, 2009 at 2:27 PM, Greg Hirson <ghir...@ucdavis.edu
<mailto:ghir...@ucdavis.edu>> wrote:
Dear list,
I have two lists: one with data and one with TRUE/FALSE values for
data I want to further analyze (see example below). I have been
able to use a for loop to extract the data that I want to keep,
but think that there probably exists a way to do it without a
loop. Any ideas?
#sample data
set.seed(100)
example = list(letters[1:10], letters[1:10], letters[1:10])
ind = list(as.logical(sample(0:1, 10, rep=TRUE)),
as.logical(sample(0:1, 10, rep=TRUE)), as.logical(sample(0:1, 10,
rep=TRUE)), as.logical(sample(0:1, 10, rep=TRUE)))
#loop method
for (i in 1:length(example)) print(example[[i]][ind[[i]]])
#result
[1] "c" "g" "i"
[1] "a" "b" "e" "f" "j"
[1] "a" "b" "c" "d" "g" "h" "i"
Thank you for the help.
Greg
--
Greg Hirson
ghir...@ucdavis.edu <mailto:ghir...@ucdavis.edu>
Graduate Student
Agricultural and Environmental Chemistry
1106 Robert Mondavi Institute North
One Shields Avenue
Davis, CA 95616
______________________________________________
R-help@r-project.org <mailto:R-help@r-project.org> mailing list
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PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
<http://www.r-project.org/posting-guide.html>
and provide commented, minimal, self-contained, reproducible code.
--
Jim Holtman
Cincinnati, OH
+1 513 646 9390
What is the problem that you are trying to solve?
--
Greg Hirson
ghir...@ucdavis.edu
Graduate Student
Agricultural and Environmental Chemistry
1106 Robert Mondavi Institute North
One Shields Avenue
Davis, CA 95616
______________________________________________
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.
