Hello,
I have a problem that I am trying to solve and I am not sure how to
do it in R.
Suppose, that 16 numbers are choosen at random from 0 to 9, what's
the probability that their average will be between 4 and 6. I typed
the following code:
set.seed(100)
sample(0:9, 16, replace =TRUE)
[1] 3 2 5 0 4 4 8 3 5 1 6 8 2 3 7 6
Is what I got, however I realize the set.seed function locks in the
number I get every time.
My question is in order to run a true random sample, wouldn't I have
to use the runif function? And then deliminate the sample to show the
numbers that lie between 4 and 6? If that's the case, how do I do that?
Davia S. Cox
517-575-8031 cell
davia.cox at gmail.com
"Human potential, though not always apparent, is there waiting to be
discovered and invited forth." -William W. Purkey
Please disregard this message and don't post it to the web. I found the answer. Thanks Davia S. Cox 517-575-8031 cell davia.cox at gmail.com "Human potential, though not always apparent, is there waiting to be discovered and invited forth." -William W. Purkey On Dec 13, 2005, at 6:20 AM, Davia Cox wrote:> Hello, > > I have a problem that I am trying to solve and I am not sure how to > do it in R. > > Suppose, that 16 numbers are choosen at random from 0 to 9, what's > the probability that their average will be between 4 and 6. I typed > the following code: > > set.seed(100) > sample(0:9, 16, replace =TRUE) > [1] 3 2 5 0 4 4 8 3 5 1 6 8 2 3 7 6 > > Is what I got, however I realize the set.seed function locks in the > number I get every time. > My question is in order to run a true random sample, wouldn't I > have to use the runif function? And then deliminate the sample to > show the numbers that lie between 4 and 6? If that's the case, how > do I do that? > > > Davia S. Cox > 517-575-8031 cell > davia.cox at gmail.com > > "Human potential, though not always apparent, is there waiting to > be discovered and invited forth." -William W. Purkey > > > >
On 12/13/05 6:20 AM, "Davia Cox" <davia.cox at gmail.com> wrote:> Hello, > > I have a problem that I am trying to solve and I am not sure how to > do it in R. > > Suppose, that 16 numbers are choosen at random from 0 to 9, what's > the probability that their average will be between 4 and 6. I typed > the following code: > > set.seed(100) > sample(0:9, 16, replace =TRUE) > [1] 3 2 5 0 4 4 8 3 5 1 6 8 2 3 7 6 > > Is what I got, however I realize the set.seed function locks in the > number I get every time.Just don't use set.seed() before every run (unless you want to always get the same answers). Set.seed() is available to allow you to generate reproducible results, so not using it means that you will get a different set of random numbers every time you run your "sample" from above. Sean
Davia Cox wrote:> Hello, > > I have a problem that I am trying to solve and I am not sure how to > do it in R. > > Suppose, that 16 numbers are choosen at random from 0 to 9, what's > the probability that their average will be between 4 and 6. I typed > the following code: > > set.seed(100) > sample(0:9, 16, replace =TRUE) > [1] 3 2 5 0 4 4 8 3 5 1 6 8 2 3 7 6 > > Is what I got, however I realize the set.seed function locks in the > number I get every time.Yes, that's what set.seed is intended to do... otherwise don't use set.seed (and make your work unreproducible).> My question is in order to run a true random sample,We have to disappoint you: Your computer cannot generate "true random samples". > wouldn't I have> to use the runif function? And then deliminate the sample to show theNo, if you want integers, the sample above fits perfectly well.> numbers that lie between 4 and 6? If that's the case, how do I do that?Is this a homework question? Uwe Ligges> > Davia S. Cox > 517-575-8031 cell > davia.cox at gmail.com > > "Human potential, though not always apparent, is there waiting to be > discovered and invited forth." -William W. Purkey > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html