[R] Marginal and Discrete Effects of a Logit

[Robi Ragan]

I am trying to compute the marginal effects from a logit.

dPr(y=1)/dx_k

and

delta Pr(y=1|xbar)/ delta x_k

I have searched the archives and seen the question asked, but never an
answer given. Is this possible in either lrm or glm?

Thanks,

-- 

Robi