set.seed and for loop
That wouldn't work because the seed is for the first iteration. Random numbers are generated by a seed, after which the seed changes (I don't know the mechanism for changing the seed in R, but it's static) That means that, if you set the seed to 1001, and then run runif function 50 times, you'll get 50 different sets of random numbers. If you reset the seed to 1001 and then run runif again, the result will be the same as data[[1]], not [[23]]. And you can't just set the seed to 1023 because that's not how the seed changes. I think Jim's suggestion was the best. I was thinking of that but I couldn't remember how to extract the seed. Sam
On Thu, Jun 9, 2011 at 12:23 PM, Samuel Le <Samuel.Le at srlglobal.com> wrote:
What about:
set.seed(1001)
total <- 0
data <- vector("list", 30)
for(i in 1:30) {
?data[[i]] <- runif(50)
}
set.seed(1001)
data[[23]] <- runif(50)
HTH
Samuel
-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of Soyeon Kim
Sent: 09 June 2011 16:15
To: r-help
Subject: [R] set.seed and for loop
Dear All,
This is hard to describe so I made a simple example.
set.seed(1001)
total <- 0
data <- vector("list", 30)
for(i in 1:30) {
?data[[i]] <- runif(50)
}
Let's call a data set runif(50).
While the for loop is running, 100 data sets ?are generated.
I want to restore 23th data set (the data set generated in 23th for
loop) without the loop.
I've tried set.seed(1023) runif(50)
but this is different data from the data set gotten from 23th for loop.
How can I get 23th data set without the loop?
Thank you,
Soyeon
______________________________________________ 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. __________ Information from ESET NOD32 Antivirus, version of virus signature database 6193 (20110609) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 6193 (20110609) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ______________________________________________ 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.