Multinomial logit (mnrfit) - How can I calculate partial derivatives of probabilities ( aka : partial effects on the probabilities )

Dear All,

I have estimated a multinomial logit regression on MATLAB using mnrfit, and I got the B matrix with the coefficients, the STATS matrix with the statistics and the DEV matrix with the deviance.

What I would now like to have is the "partial derivatives of probabilities" wrt to the individual variables.. also known as "partial effects of the characteristics on the probabilities" (ΔProb),and a way to know which one of them are statistically significant. I believe I have to use mnrval somehow but I don't really know.

Can somebody let me know how to get these ?

Thank a lot in advance