[R] permutation and reshuffling

Greg Snow
Tue, 01 Sep 2009 14:59:37 -0000

Look at ?sample for how to shuffle/permute a single vector (or rows of a data
frame/matrix) and ?replicate for a way to do it a bunch of times and return the
results in a nice form.

Hope this helps,

--
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111


> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Yonatan Nissenbaum
> Sent: Tuesday, September 01, 2009 1:35 AM
> To: r-help at r-project.org
> Subject: [R] permutation and reshuffling
>
> Hi,
>
>
>
> I'm looking for an efficient code that will enable me to reshuffle data
> (phenotype) for certain number of individuals and creating a loop that
> will
> randomly simulate it for 10000 times *(permutation)*. I also need to
> find
> how I keep the information (p value for each SNP) gathered for all the
> 10000
> iterations.
>
> My data set looks like this (n=500):
>
> Individual #
>
> Phenotype
>
> SNP1
>
> SNP2
>
> SNP3
>
> SNP4
>
> SNP5
>
> SNP6
>
> SNP7
>
> SNP8
>
> SNP9
>
> SNP10
>
> SNP11
>
> SNP12
>
> 1
>
> 0
>
> T
>
> T
>
> G
>
> G
>
> A
>
> C
>
> G
>
> T
>
> A
>
> A
>
> T
>
> C
>
> 2
>
> 1
>
> A
>
> T
>
> C
>
> G
>
> A
>
> C
>
> G
>
> T
>
> A
>
> G
>
> T
>
> C
>
>
>
> Many thanks,
>
>
>
> Jonathan
>
> 	[[alternative HTML version deleted]]
>
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