activePar {maxLik} | R Documentation |
Return a logical vector, indicating which parameters were free under maximisation, as opposed to the fixed parameters, treated as constants.
activePar(x, ...) ## Default S3 method: activePar(x, ...)
x |
object, created by a maximisation routine, or derived from a
maximisation object. Currently only |
... |
further arguments for methods |
Several optimisation routines allow the user to fix some parameter values (or do it automatically in some cases). For gradient or Hessian based inference one has to know which parameters carry optimisation-related information.
A logical vector, indicating whether the parameters were free to change during optimisation algorithm.
Ott Toomet, otoomet@econ.au.dk
# a simple two-dimensional exponential hat f <- function(a) exp(-a[1]^2 - a[2]^2) # # maximize wrt. both parameters free <- maxNR(f, start=1:2) summary(free) # results should be close to (0,0) activePar(free) # allow only the second parameter to vary cons <- maxNR(f, start=1:2, activePar=c(FALSE,TRUE)) summary(cons) # result should be around (1,0) activePar(cons)