binary order combinations
names <- sprintf("V%d", 1:4);
n <- length(names);
stopifnot(n <= 32); # Theoretical upper limit
x <- matrix(intToBits(1:(2^n-1)), ncol=2^n-1);
x <- x[1:n,,drop=FALSE];
keys <- apply(x, MARGIN=2, FUN=function(z) paste(names[as.logical(z)],
collapse=":"));
print(keys);
[1] "V1" "V2" "V1:V2" "V3"
[5] "V1:V3" "V2:V3" "V1:V2:V3" "V4"
[9] "V1:V4" "V2:V4" "V1:V2:V4" "V3:V4"
[13] "V1:V3:V4" "V2:V3:V4" "V1:V2:V3:V4"
/H
On Fri, Sep 5, 2008 at 8:23 AM, Dimitri Liakhovitski <ld7631 at gmail.com> wrote:
I am not sure it can do it. Besides, I ran a test of combos from quantreg:
library(quantreg)
H<-1:3
test.combos<-lapply(1:3,function(x)
{combn(H,x)
})
Every time I tried it crashed my R...
:(
Dimitri
On 9/5/08, roger koenker <rkoenker at uiuc.edu> wrote:
Does ?combos in the quantreg package do what you want? url: www.econ.uiuc.edu/~roger Roger Koenker email rkoenker at uiuc.edu Department of Economics vox: 217-333-4558 University of Illinois fax: 217-244-6678 Champaign, IL 61820 On Sep 5, 2008, at 9:58 AM, Dimitri Liakhovitski wrote:
Dear all!
I have a vector of names
names<-("V1", "V2", "V3",....., "V15")
I could create all possible combinations of these names (of all
lengths) using R:
combos<-lapply(1:15,function(x)
{combn(names,x)
})
I get a list with all possible combinations of elements of 'names'
that looks like this (just the very beginning of it):
[[1]] - the first element contains all combinations of 1 name
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [,13]
[,14]
[1,] "V1" "V2" "V3" "V4" "V5" "V6" "V7" "V8" "V9" "V10" "V11" "V12" "V13"
"V14"
[,15] [1,] "V15" [[2]] - the second element contains all possible combinations of 2 names [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [,13] [1,] "V1" "V1" "V1" "V1" "V1" "V1" "V1" "V1" "V1" "V1" "V1" "V1" "V1" [2,] "V2" "V3" "V4" "V5" "V6" "V7" "V8" "V9" "V10" "V11" "V12" "V13" "V14" . . . etc. My question is: Is there any way to re-arrange all sub-elements of the above list (i.e., all possible combinations of names such as V1, V1:V3, V1:V2:V4:V5) in a binary system order. More specifically, according to this system: V1=1 V2=2 V3=4 V4=8 V5=16, etc.... So, I'd like those combinations to be arranged in a vector in the following order: 1. V1 (because V1=1) 2. V2 (because V2=2) 3. V1:V2 (because V1=1 and V2=2 so that 1+2=3) 4. V3 (because V3=4) 5. V1:V3 (because V1=1 and V3=4 so that 1+4=5) 6. V2:V3 (because V2=2 and V3=4 so that 2+4=6) 7. V1:V2:V3 (because V1=1 and V2=2 and V3=4 so that 1+2+4=7) 8. V4 (because V4=8) etc. Is it at all possible? Or maybe there is a way to create the name combinations in such an order in the first place? Thank you very much! Dimitri Liakhovitski
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______________________________________________ R-help at 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.