st: derivatives using _me_derb

["Mike Will" <mystata@hotmail.com>]

Hi Stata-Listers,

I am having trouble using _me_derb (dF/dB).  Here is my syntax:
**************************************************************
logit y x1 x2 x3
matrix X=(1, 0.5, -0.9, 1.2)
_me_derb X 4 predopt lny
di r(dmdb)
**************************************************************

Here I am trying to take the derivative of (1/(1+(exp(XB))^(-1)), or 
predicted probability with respect to B with the X matrix of (1, 0.5, -0.9, 
1.2).  As no help file is available for this ado file, I am getting error 
message whihc is of little informative value.  Any input? thanks in advance.

Mike


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