d2norm.plot <-
function (m1=0,m2=0,sd1=1,sd2=1,rho=0.8) 
{
# Plottet die zweidimensionale Normalverteilung
par(pty="s")
x<-seq(-3,3,0.1)
y<-seq(-3,3,0.1)
I<-length(x)
J<-length(y)
f<-matrix(rep(0,I*J),ncol=J)
for(i in 1:I){
  for(j in 1:J){
     f[i,j]<-d2norm(x[i],y[j],m1=m1,m2=m2,sd1=sd1,sd2=sd2,rho=rho)
     }  
  }  
# persp(x,y,f)
 contour(x,y,f)
# image(x,y,f)
title(paste("rho=",as.character(rho)))
}