Under appropriate circumstances, the fitted model object
contains the history of evaluations of the objective function
that were performed by the optimisation algorithm. This history is
extracted by traj
.
The result is a data frame containing the input parameter values for
the objective function, and the corresponding value of the objective
function, that were considered by the optimisation algorithm. This
data frame also belongs to the class "traj"
which has
methods for plot
, print
and other purposes.