Dear ALL I want to simulate data from Multivariate normal distribution. GE.N<-mvrnorm(25,mu,S) S <-matrix(rep(0,10000),nrow=100) for( i in 1:100){sigma<-runif(100,0.1,10);S [i,i]=sigma[i];mu<-runif(100,0,10)} for (i in 1:20){for (j in 1:20){if (i != j){S [i,j]=0.3*sigma[i]*sigma[j]}}} for (i in 21:40){for (j in 21:40){if (i != j){S [i,j]=0.3*sigma[i]*sigma[j]}}} for (i in 41:60){for (j in 41:60){if (i != j){S [i,j]=0.3*sigma[i]*sigma[j]}}} for (i in 61:80){for (j in 61:80){if (i != j){S [i,j]=0.3*sigma[i]*sigma[j]}}} for (i in 81:100){for (j in 81:100){if (i != j){S [i,j]=0.3*sigma[i]*sigma[j]}}} How should I do when S is not positive definite matrix? I saw this error: 'Sigma' is not positive definite.
best regards, Sara [[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.