Re: [R] Obtaining SE from the hessian matrix

2004-02-20 Thread Timur Elzhov
On Thu, Feb 19, 2004 at 09:22:09AM -0800, Thomas Lumley wrote: So, what is the _right_ way for obtatining SE? Why two those formulas above differ? If you are maximising a likelihood then the covariance matrix of the estimates is (asymptotically) the inverse of the negative of the Hessian.

Re: [R] Obtaining SE from the hessian matrix

2004-02-19 Thread Thomas Lumley
On Thu, 19 Feb 2004, Timur Elzhov wrote: So, what is the _right_ way for obtatining SE? Why two those formulas above differ? If you are maximising a likelihood then the covariance matrix of the estimates is (asymptotically) the inverse of the negative of the Hessian. The standard errors are

Re: [R] Obtaining SE from the hessian matrix

2004-02-19 Thread Spencer Graves
Minor correction: Most likely, Prof. Lumley's statement is correct. However, as I'm sure he knows, it depends on what you are maximizing or minimizing: If you are maximizing the log(likelihood), then the NEGATIVE of the hessian is the observed information. This latter should be