library(MASS)
options(digits=3)
set.seed(1234)
mean <- c(230.7,146.7,3.6)
sigma <- matrix(c(15360.8,6721.2,-47.1,6721.2,4700.9,-16.5,-47.1,-16.5,0.3),nrow=1,ncol=3)
mydata <- mvrnorm(n=500,mean,sigma)    #总弹出来“ incompatible arguments”不兼容的参数
mydata <- as.data.frame(mydata)
names(mydata) <- c('y','x1','x2')
dim(mydata)


“mydata <- mvrnorm(n=500,mean,sigma)”这句总出问题，总弹出来“ incompatible arguments”不兼容的参数。
哪位大神能帮忙解答一下~~~谢谢！