Hi, As a slight aside, did you mean pseudo-random or quasi-random?
http://en.wikipedia.org/wiki/Pseudorandom_number_generator http://en.wikipedia.org/wiki/Low-discrepancy_sequence runif gives a sequence of pseudo-random numbers, for quasi-random numbers you will need something else, for example the Sobol generator from http://cran.r-project.org/web/packages/randtoolbox/index.html. Martyn -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Frederico Mestre Sent: 05 August 2014 11:28 To: r-help@r-project.org Subject: [R] Generate quasi-random positive numbers Hello all: Is it possible to generate quasi-random positive numbers, given a standard deviation and mean? I need all positive values to have the same probability of selection (uniform distribution). Something like: runif(10, min = 0, max = 100) This way I'm generating random positive numbers from a uniform distribution. However, using runif I can't previously select SD and mean (as in rnorm). Alternatively, I'm able to generate a list of quasi-random numbers given a SD and a mean. b <- (sqrt(SD^2*12)+(MEAN*2))/2 a <- (MEAN*2) - b x1 <- runif(N,a,b) However, negative values might be included, since "a" can assume a negative value. Any help? Thanks, Frederico [[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. ________________________________________________________________________ This e-mail has been scanned for all viruses by Star.\ _...{{dropped:3}} ______________________________________________ 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.
