Here is one way of doing it: # generate 200 x 2500 samples and then check them c <- qnorm(0.05) i <- 2500 iter <- 200 x <- matrix(rnorm(i * iter, 0, 1) < c,nrow=i) # TRUE/FALSE according to condition # now create the counts x.c <- colSums(x) # write out to a file 1 value on each line cat(x.c, file='/tempxx.txt', sep="\n")
On Wed, Jul 23, 2008 at 2:47 PM, Eric C Banfield <[EMAIL PROTECTED]> wrote: > > Greetings. This is very basic but we can't figure it out. The following > simple code counts how many values land in the "tail" (below a quantile) of > a standardized normal distribution of random numbers. First two commands > are inputs: >> c <-0.05 >> i <-2500 > Second two commands are formulas I want to repeat many times (sort of like > an Excel/VBA macro) using those same inputs: >> r <- rnorm(i,0,1) >> n <- length(r[r<qnorm(c)]) > > I believe I could also run this as one line: r <- rnorm(i); n <- > length(r[r<qnorm(c)]) > > "n" will vary around 125. Each time I run the code -- say 262 times -- > I'll get a new "n". I want to save all those "n"s in a file for Excel. > > I can use cat(n,file="c:/temp/file.csv") to store the value of n in a *.csv > file. But: > > 1. How do I tell R each time I run the above to append in that file the new > value of 'n' to the list of prior 'n's? > e.g., Suppose the first run I get n=125, second run I get n=127, and so on. > I want a file that will have 125 in the first row, 127 the second, and so > on, > I tried cat(n,file="c:/temp/file.csv", sep=" ") but it holds only the > single, latest value of n. > I tried file.append but then I get 125127. > > 2. How do I tell R to run or loop through the above lines hundreds of > times, e.g., j = 262? -- rather like an Excel/VBA macro?) > So if I can make this iterate 262 times, I'll have a list or column of 262 > numbers. > > Thanks -- Eric. > > ______________________________________________ > 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.
