search for: optimhessian

Displaying 1 result from an estimated 1 matches for "optimhessian".

2012 Nov 15
1
hessian fails for box-constrained problems when close to boundary?
Hi I am trying to recover the hessian of a problem optimised with box-constraints. The problem is that in some cases, my estimates are very close to the boundary, which will make optim(..., hessian=TRUE) or optimHessian() fail, as they do not follow the box-constraints, and hence estimate the function in the unfeasible parameter space. As a simple example (my problem is more complex though, simple param transformations do not apply ashere), imagine estimating mu and sigma (restricted to be >0) of a simple norm...