## example of computing MNP probabilites
## here Xa has the prices of each of the 3 alternatives
Xa = matrix(c(1,.5,1.5), nrow=1)
X = createX(p=3, na=1, nd=NULL, Xa=Xa, Xd=NULL, DIFF=TRUE)
beta = c(1,-1,-2) ## beta contains two intercepts and the price coefficient
Sigma = matrix(c(1, 0.5, 0.5, 1), ncol=2)
mnpProb(beta, Sigma, X)
Run the code above in your browser using DataLab