rescale_pars {mrds} | R Documentation |
This will calculate the rescaling needed when covariates to be included in
the scale of the detection function are "too big". Based on code from
optimx
.
rescale_pars(initialvalues, ddfobj)
initialvalues |
starting values for the optimisation |
ddfobj |
detection function object |
Derivative-free methods like nlminb are sensitive to the parameters being poorly scaled. This can also cause problems for quasi-Newton methods too (at least, bad scaling won't _help_ the optimisation). So here we rescale the parameters if necessary (unless we already got scaling from control)
David L Miller