I am not sure of this, but I think you can unset the seed by removing the dataset .Random.seed from the global environment. E.g.,
> set.seed(1) > runif(5) [1] 0.2655087 0.3721239 0.5728534 0.9082078 0.2016819 > rm(list=".Random.seed", envir=globalenv()) > runif(5) [1] 0.5952379 0.3355091 0.8820192 0.7633754 0.8064312 > > > set.seed(1) > runif(5) # same as before [1] 0.2655087 0.3721239 0.5728534 0.9082078 0.2016819 > rm(list=".Random.seed", envir=globalenv()) > runif(5) # different [1] 0.52023610 0.73407695 0.08824484 0.26977430 0.80089250 Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf > Of Nordlund, Dan (DSHS/RDA) > Sent: Monday, March 18, 2013 12:44 PM > To: C W > Cc: r-help > Subject: Re: [R] How to stop set.seed() besides exiting out of R? > > No, you cannot unset the seed. You can set it to a different value, but a > the random > number generators always need a starting seed. If you don’t set one, R will > set one for > you , you just won’t know what it is. And as a practical matter, given a > sequence of > random numbers you can’t tell what the starting seed was. That is the point > of good > random number generators. Each sequence of random numbers for most intents > and > purposes can be considered independent from previous sets of numbers. > > Hope this is helpful, > > Dan > > Daniel J. Nordlund > Washington State Department of Social and Health Services > Planning, Performance, and Accountability > Research and Data Analysis Division > Olympia, WA 98504-5204 > > From: C W [mailto:tmrs...@gmail.com] > Sent: Monday, March 18, 2013 12:19 PM > To: Nordlund, Dan (DSHS/RDA) > Cc: r-help > Subject: Re: [R] How to stop set.seed() besides exiting out of R? > > Yes, I agree with you. I guess what I was really looking for is a function > like > UNset.seed()? > > By having set.seed(), I can have reproducible code. But what if I want to > check my work > against what's produced from set.seed(100)? > > I really want to escape from the shadow of set.seed(), can I unset it? > On Mon, Mar 18, 2013 at 3:07 PM, Nordlund, Dan (DSHS/RDA) > <nord...@dshs.wa.gov<mailto:nord...@dshs.wa.gov>> wrote: > As I understand it, how R “‘normally” does it is to use the system clock to > set the seed > once per session, unless you use set.seed() to set a new seed. You chose to > set the seed > to a different value. But from that point on, the pseudo random number > generation > continues in the same way it “normally” does. In your code below, each of > your 100 > histograms will be different. If you then execute the for loop again (but > not the > set.seed(100) statement), you will get a different set of histograms. The > only way you > would be “confined to set.seed(100)” is if you keep resetting the seed to 100. > > Dan > > Daniel J. Nordlund > Washington State Department of Social and Health Services > Planning, Performance, and Accountability > Research and Data Analysis Division > Olympia, WA 98504-5204 > From: C W [mailto:tmrs...@gmail.com<mailto:tmrs...@gmail.com>] > Sent: Monday, March 18, 2013 11:50 AM > To: Nordlund, Dan (DSHS/RDA) > Cc: r-help > Subject: Re: [R] How to stop set.seed() besides exiting out of R? > > set.seed(100) > for (i in 1:100){ > a <- rnorm(1000, mean=0, sd=1) > hist(a) > } > > #Now say, I want to simulate without being confined to set.seed(100), I just > want to get > a simulation like how R "normally" does it. > > Mike > On Mon, Mar 18, 2013 at 2:40 PM, Nordlund, Dan (DSHS/RDA) > <nord...@dshs.wa.gov<mailto:nord...@dshs.wa.gov><mailto:nord...@dshs.wa.gov< > mailto:nord...@dshs.wa.gov>>> wrote: > > -----Original Message----- > > From: > > r-help-boun...@r-project.org<mailto:r-help-boun...@r-project.org><mailto:r- > help-boun...@r-project.org<mailto:r-help-boun...@r-project.org>> > [mailto:r-help- > bounces@r-<mailto:r-help-bounces@r-><mailto:r-help-bounces@r-<mailto:r-help- > bounces@r->> > > project.org<http://project.org><http://project.org>] On Behalf Of C W > > Sent: Monday, March 18, 2013 11:27 AM > > To: r-help > > Subject: [R] How to stop set.seed() besides exiting out of R? > > > > Hi list, > > > > I am curious how to stop the set.seed(), I don't want the same repeated > > random number. I know I can set it to a different seed, but I don't > > want > > to go through the trouble of setting different seed every time. > > > > Thanks, > > Mike > > > Can you show us how you are using set.seed() that results in getting the same > sequence > repeatedly? If you are doing simulations in a loop, then set the seed once, > outside the > loop. Otherwise, I am not sure what you are doing that causes problems. A > reproducible > example would really help. > > Dan > > Daniel J. Nordlund > Washington State Department of Social and Health Services > Planning, Performance, and Accountability > Research and Data Analysis Division > Olympia, WA 98504-5204 > > ______________________________________________ > R-help@r-project.org<mailto:R-help@r-project.org><mailto:R-help@r- > project.org<mailto: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. > > [[alternative HTML version deleted]] > > > ______________________________________________ > R-help@r-project.org<mailto: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. > > > [[alternative HTML version deleted]] ______________________________________________ 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.