[Rd] optim: gr called at different parameter values than previous fn call if hessian=T (PR#1354)

w.huber@dkfz.de w.huber@dkfz.de
Sun, 3 Mar 2002 19:04:39 +0100 (MET)

Full_Name: Wolfgang Huber
Version: 1.4.0
Submission from: (NULL) (

The documentation to "optim" (packpage base) says "It is guaranteed that `gr' 
will be called immediately after a call to `fn' at the same parameter values."
I found this not to be true when I called 


When I changed this to hessian=F), every single call to gr was indeed preceded
a call to fn at the same parameter values. Apparently the final calculation of 
the hessian violates the above guarantee. 

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