The extras are:
Time to train the model(s) that produced the points. Only the first slot of the vector is used (if we have multiple points), rest are NA.
Time needed to propose the point. If we have individual timings from the proposal mechanism, we have one different value per point here. If all were generated in one go, we only have one timing, we store it in the slot for the first point, rest are NA.
Possible Error Messages. If point-producing model(s) crashed they are replicated for all n points, if only one error message was passed we store it for the first point, rest are NA.
Type of point proposal. Possible values are
Points actually not proposed, but in the initial design.
Here x is a placeholder for the selected infill criterion, e.g., infill\_ei for expected improvement.
Uniformly sampled points added additionally to the proposed points.
If filtering of proposed points located too close to each other is active, these are replaced by random points.
final.evals is set in
makeMBOControl: Final evaluations of the proposed solution to reduce noise in y.
Weight vector sampled for multi-point ParEGO
Depending on the chosen infill criterion there will be additional columns, e.g.
mean for the Expected Improvement)
Moreover, the user may pass additional “user extras” by appending a named list of scalar values to the return value of the objective function.