Hi r-help-boun...@r-project.org napsal dne 06.10.2010 11:51:37:
> > Dear all, > > > > I need to do a loop in R, but I am not sure the software is generating "n" > times the variables I request differently. When I ask to print the last matrix > created, I just can see the loop for n=1. > > To be more precise, supose I need to simulate 10 times one variable and I want > to fit the 10 variables simulated in a matrix. I dont really know what I am > doing wrong, but I just can see 1 variable created. > > Below follows an example of what I want: > > > > rm(list=ls()) #remove almost everything in the memory Not in memory but in file .Rdata on your PC too when you end your session > > > > set.seed(180185) > > > > #loop: create 10 times the variables (u1,u2,u3,u4,u5) > > > > for (i in 1:10){ > u1 <- c(runif(200,0,1)) > u2 <- c(runif(200,0,1)) > u3 <- c(runif(200,0,1)) > u4 <- c(runif(200,0,1)) > u5 <- c(runif(200,0,1)) Five vectors with 200 numbers each despite of excessive c() construction. > u <- c(u1,u2,u3,u4,u5) vector of length 1000 > mu <- matrix(u, nrow=1000, ncol=1) changed to matrix > } all made 10 times. Imagine you do a loop for (i i 10) { copy "file1" to "file2" } what do you expect as a result? Ten files or only one file? When you want a matrix with 10 colums and 1000 rows you can set it before your loop mu <- matrix(NA, nrow=1000, ncol=10) and use mu[,i] <- u as the last row in your loop. But what is wrong with mu <- matrix(runif(10000, 0,1), nrow=1000, ncol=10) for getting such matrix. Regards Petr > > > As you can see, when I print(mu), I just can see a matrix with the vector u in > one column. I also tried to increase the number of columns to 10 (or i), but > the matrix will have 10 times the same vector. And what I need is like a Monte > Carlo simulation, where I have to simulate 10 times the variables above. > > > > Am I doing something wrong? > > > > Thanks in advance! > > > > Julia > > [[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. ______________________________________________ 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.