Hi there,
    
    recently I wrote a UDF in order to calculate and plot the bivariate
    normal distribution.
    Now I found the ghk function and tried to replicate the results, but
    unfortunately in vain.
    I think that I miss-specify the second and third argument. How is a
    correct?
    
    <hansl>
    matrix U=mnormal(400,2)
    matrix A =seq(0,400)/-100 #lower bound    
    A=A'~A'
    matrix B =seq(0,400)/100 #upper bound    
    B=B'~B'
    matrix vcv=unvech({1;0;2})
    matrix f = ghk(cholesky(vcv),A,B,U')
    
    nulldata 400 --preserve
    series x1=U[,1]
    series x2=U[,2]
    series fxy=f[1:400]
    <hansl>
    
    Thanks in advance
    Leon Unger