Random Sample

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Random Sample

Xiaoxi Gao

Hello R users,
Here is my question about generating random sample. How to set the random seed to recreate the same random numbers?  For example, 10 random numbers is generated from N(0,1), then "runif(10)" is used.What if I want to get the same 10 random numbers when I run runif(10) again? Is it possible?I think .Random.seed should be used here.
Thanks.
Xiaoxi      
        [[alternative HTML version deleted]]

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Re: Random Sample

Jonathan P Daily
Use "set.seed()"
--------------------------------------
Jonathan P. Daily
Technician - USGS Leetown Science Center
11649 Leetown Road
Kearneysville WV, 25430
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"Is the room still a room when its empty? Does the room,
 the thing itself have purpose? Or do we, what's the word... imbue it."
     - Jubal Early, Firefly



From:
Xiaoxi Gao <[hidden email]>
To:
R Help <[hidden email]>
Date:
11/08/2010 03:59 PM
Subject:
[R] Random Sample
Sent by:
[hidden email]




Hello R users,
Here is my question about generating random sample. How to set the random
seed to recreate the same random numbers?  For example, 10 random numbers
is generated from N(0,1), then "runif(10)" is used.What if I want to get
the same 10 random numbers when I run runif(10) again? Is it possible?I
think .Random.seed should be used here.
Thanks.
Xiaoxi  
                 [[alternative HTML version deleted]]

______________________________________________
[hidden email] 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.



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Re: Random Sample

Erik Iverson-3
In reply to this post by Xiaoxi Gao
?set.seed is what you're looking for

Xiaoxi Gao wrote:

> Hello R users,
> Here is my question about generating random sample. How to set the random seed to recreate the same random numbers?  For example, 10 random numbers is generated from N(0,1), then "runif(10)" is used.What if I want to get the same 10 random numbers when I run runif(10) again? Is it possible?I think .Random.seed should be used here.
> Thanks.
> Xiaoxi      
> [[alternative HTML version deleted]]
>
> ______________________________________________
> [hidden email] 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.

______________________________________________
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Re: Random Sample

Jorge I Velez
In reply to this post by Xiaoxi Gao
Hi Xiaoxi,

Take a look at the following:

> set.seed(123)
> rnorm(10)
 [1] -0.56047565 -0.23017749  1.55870831  0.07050839  0.12928774  1.71506499
 [7]  0.46091621 -1.26506123 -0.68685285 -0.44566197
> rnorm(10)
 [1]  1.2240818  0.3598138  0.4007715  0.1106827 -0.5558411  1.7869131
 0.4978505
 [8] -1.9666172  0.7013559 -0.4727914
> set.seed(123)
> rnorm(10)
 [1] -0.56047565 -0.23017749  1.55870831  0.07050839  0.12928774  1.71506499
 [7]  0.46091621 -1.26506123 -0.68685285 -0.44566197

and check ?set.seed().

HTH,
Jorge


On Mon, Nov 8, 2010 at 3:57 PM, Xiaoxi Gao <> wrote:

>
> Hello R users,
> Here is my question about generating random sample. How to set the random
> seed to recreate the same random numbers?  For example, 10 random numbers is
> generated from N(0,1), then "runif(10)" is used.What if I want to get the
> same 10 random numbers when I run runif(10) again? Is it possible?I think
> .Random.seed should be used here.
> Thanks.
> Xiaoxi
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> [hidden email] 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.
>

        [[alternative HTML version deleted]]

______________________________________________
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Re: Random Sample

Giovanni Petris
Here is an example of what I think the original poster wanted to
achieve.

> rnorm(10)
 [1] -1.2165869 -0.4698460 -0.4209811 -1.4856052  0.3765774 -1.3822470
 [7]  0.2818458  0.5500957 -1.1474455 -1.2221257
> x <- .Random.seed
> runif(10)
 [1] 0.5610780 0.5911841 0.5868183 0.3833801 0.7397059 0.4973270 0.6544219
 [8] 0.1257485 0.2756357 0.5672207
> .Random.seed <- x
> runif(10)
 [1] 0.5610780 0.5911841 0.5868183 0.3833801 0.7397059 0.4973270 0.6544219
 [8] 0.1257485 0.2756357 0.5672207
 
Best,
Giovanni Petris

On Mon, 2010-11-08 at 16:05 -0500, Jorge Ivan Velez wrote:

> Hi Xiaoxi,
>
> Take a look at the following:
>
> > set.seed(123)
> > rnorm(10)
>  [1] -0.56047565 -0.23017749  1.55870831  0.07050839  0.12928774  1.71506499
>  [7]  0.46091621 -1.26506123 -0.68685285 -0.44566197
> > rnorm(10)
>  [1]  1.2240818  0.3598138  0.4007715  0.1106827 -0.5558411  1.7869131
>  0.4978505
>  [8] -1.9666172  0.7013559 -0.4727914
> > set.seed(123)
> > rnorm(10)
>  [1] -0.56047565 -0.23017749  1.55870831  0.07050839  0.12928774  1.71506499
>  [7]  0.46091621 -1.26506123 -0.68685285 -0.44566197
>
> and check ?set.seed().
>
> HTH,
> Jorge
>
>
> On Mon, Nov 8, 2010 at 3:57 PM, Xiaoxi Gao <> wrote:
>
> >
> > Hello R users,
> > Here is my question about generating random sample. How to set the random
> > seed to recreate the same random numbers?  For example, 10 random numbers is
> > generated from N(0,1), then "runif(10)" is used.What if I want to get the
> > same 10 random numbers when I run runif(10) again? Is it possible?I think
> > .Random.seed should be used here.
> > Thanks.
> > Xiaoxi
> >        [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > [hidden email] 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.
> >
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> [hidden email] 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.

--

Giovanni Petris  <[hidden email]>
Associate Professor
Department of Mathematical Sciences
University of Arkansas - Fayetteville, AR 72701
Ph: (479) 575-6324, 575-8630 (fax)
http://definetti.uark.edu/~gpetris/

______________________________________________
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