这是关于绘制一组观测值的等值线命令，为何两部分绘制出来的图像差距那么大？

norm.cop<-ellipCopula(family="normal",param=0.7,dim=2)
norm.mvdc<-mvdc(copula=norm.cop,margins=c("norm","norm"),paramMargins=list(list(mean=0,sd=2),list(mean=1,sd=0.5)))
xx<-rMvdc(10000,norm.mvdc)
zz = HPDregionplot(cbind(xx[,1],xx[,2]),prob = 0.95,xlim=c(-5,5),ylim=c(-5,5),add=FALSE,col="blueviolet",lwd=2)
con.lev1<-zz[[1]]$level
cont.01<-contour(norm.mvdc,dmvdc,xlim=c(-5,5),ylim=c(-5,5),levels= con.lev1,draw = FALSE,add=FALSE)
#/////////////////////////////////////////
norm.cop<-ellipCopula(family="normal",param=0.7,dim=2)
nn<-rCopula(10000,norm.cop)
zz = HPDregionplot(cbind(nn[,1],nn[,2]),prob = 0.95,xlim=c(-5,5),ylim=c(-5,5),add=FALSE,col="blueviolet",lwd=2)
con.lev1<-zz[[1]]$level
cont.01<-contour(norm.cop,dcopula,xlim=c(-5,5),ylim=c(-5,5),levels= con.lev1,draw = FALSE,add=FALSE)