The length of the mean vector must match the number of rows and columns of the sigma matrix. Once you give 3 entries in the mean vector you will run into the problem that the sigma you are using is not positive (semi-)definite - a variance must be the product of a matrix and its transpose.
-Bill On Tue, Mar 16, 2021 at 10:55 AM hatice gürdil <haticegurdil1...@gmail.com> wrote: > > Code a is working. But code b is given error like given below. How can I > write code b? > > > a<-rmvnorm(750, mean=c(0, 0), > + sigma=matrix(c(1, .3, .3, 1), ncol=2)) > > > head(a) > [,1] [,2] > [1,] -0.97622921 -0.87129405 > [2,] 0.54763494 0.16080131 > [3,] -1.16627647 0.31225125 > [4,] 1.72541168 2.06513939 > [5,] 0.05372489 -0.07525197 > [6,] -0.85062230 -1.02188473 > > > b<-rmvnorm(round(500,0), mean=c(0,-1), > + sigma=matrix(c(.3, 1,1,1,.3, 1, 1,1, .3), ncol=3)) > > Error in rmvnorm(round(500, 0), mean = c(0, -1), sigma = matrix(c(0.3, : > mean and sigma have non-conforming size > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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 -- To UNSUBSCRIBE and more, see 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.
