Thanks Jholtman. However, the plot didnt come out the way I envisone dit to be. On the Y axis, i should have sign changes in 1000 tosses, the range being from negative to postitive, and a straight horizontal line across y=0. The X-axis should have the toss number, range 0-1000
I'm glad u mentioned rle(x)....works perfect! jholtman wrote: > > I really depends on what you want to plot. You can plot the > cumulative count of the sign changes with: > > x <- sample(c(0,1), 1000, TRUE) > plot(cumsum(x), type='l') > > There are other things you can do. You can get a rough histogram of > the length of the run by: > >> stem(rle(x)$length) > > The decimal point is at the | > > 1 | > 00000000000000000000000000000000000000000000000000000000000000000000+201 > 1 | > 2 | > 00000000000000000000000000000000000000000000000000000000000000000000+60 > 2 | > 3 | 00000000000000000000000000000000000000000000000000000 > 3 | > 4 | 00000000000000000000000000000000000000 > 4 | > 5 | 000000000 > 5 | > 6 | 00000000 > 6 | > 7 | 00000 > > With R, almost anything is possible. > > On 10/15/07, azzza <[EMAIL PROTECTED]> wrote: >> >> Umm, yes, what you had makes a lot of sense. How would I represent that >> in a >> plot of the number of sign changes in the to Y axis, and the toss number >> (from 0 to 1000) in the x-axis? >> >> >> >> >> jholtman wrote: >> > >> > You might want to check out 'rle'. This will give you the 'lengths' >> > of runs of the same value and therefore when the value changes (sign >> > change?) you can see how often: >> > >> >> x <- sample(c(-1,1), 1000, TRUE) >> >> rle(x) >> > Run Length Encoding >> > lengths: int [1:483] 2 2 1 4 3 1 1 1 1 2 ... >> > values : num [1:483] -1 1 -1 1 -1 1 -1 1 -1 1 ... >> > >> > Here was a sample of 1000, and there were 483 changes between the >> > samples. Is this what you are looking for? >> > >> > On 10/15/07, azzza <[EMAIL PROTECTED]> wrote: >> >> >> >> >> >> Quite helpful indeed. Greatly appreciated. >> >> Another problem I had was trying to simulate an example from my book. >> >> Simulating 1000 coin tosses, and finding the frequency of sign >> changes. >> >> So >> >> how will we plot this using R? (frequency of sign changes in Y axis) >> >> >> >> >> >> >> >> >> >> Daniel Nordlund wrote: >> >> > >> >> >> -----Original Message----- >> >> >> From: [EMAIL PROTECTED] >> >> [mailto:[EMAIL PROTECTED] >> >> >> On Behalf >> >> >> Of azzza >> >> >> Sent: Sunday, October 14, 2007 10:21 PM >> >> >> To: r-help@r-project.org >> >> >> Subject: [R] Need some help >> >> >> >> >> >> >> >> >> Hi! >> >> >> I'm taking a course that requires some programming background, but >> I'm >> >> a >> >> >> complete novice in the field. >> >> >> >> >> >> when asked to generate a list of 20 uniform random numbers, is it >> >> alright >> >> >> if >> >> >> I put in >randu, and just copy-paste the first 20 numbers?? Or is >> >> there, >> >> >> as >> >> >> I suspect, a better way of calling out exactly 20 uniform random >> >> >> numbers?? >> >> >> >> >> > See ?runif >> >> > >> >> > rand_nums <- runif(20) >> >> > >> >> >> I'm also unable to solve the following problem: >> >> >> We know that on average 30% of the customers who enter a store make >> a >> >> >> purchase. Suppose 200 >> >> >> people enter the store today. Run a simulation to see how many >> >> purchases >> >> >> we >> >> >> will have today. >> >> >> >> >> > see ?sample >> >> >> number_of_purchases <- sum(sample(c(0,1), 200, prob=c(.70, .30), >> >> >> replace=TRUE)) >> >> > >> >> > Hope this is helpful, >> >> > >> >> > Dan >> >> > >> >> > Daniel Nordlund >> >> > Bothell, WA USA >> >> > >> >> > ______________________________________________ >> >> > 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. >> >> > >> >> > >> >> >> >> -- >> >> View this message in context: >> >> http://www.nabble.com/Need-some-help-tf4624513.html#a13214128 >> >> Sent from the R help mailing list archive at Nabble.com. >> >> >> >> ______________________________________________ >> >> 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. >> >> >> > >> > >> > -- >> > Jim Holtman >> > Cincinnati, OH >> > +1 513 646 9390 >> > >> > What is the problem you are trying to solve? >> > >> > ______________________________________________ >> > 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. >> > >> > >> >> -- >> View this message in context: >> http://www.nabble.com/Need-some-help-tf4624513.html#a13216156 >> Sent from the R help mailing list archive at Nabble.com. >> >> ______________________________________________ >> 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. >> > > > -- > Jim Holtman > Cincinnati, OH > +1 513 646 9390 > > What is the problem you are trying to solve? > > ______________________________________________ > 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. > > -- View this message in context: http://www.nabble.com/Need-some-help-tf4624513.html#a13225092 Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.