Callback for resetting booster parameters at each iteration
xgb.cb.reset.parameters(new_params)An xgb.Callback object, which can be passed to xgb.train() or xgb.cv().
List of parameters needed to be reset.
Each element's value must be either a vector of values of length nrounds
to be set at each iteration,
or a function of two parameters learning_rates(iteration, nrounds)
which returns a new parameter value by using the current iteration number
and the total number of boosting rounds.
Note that when training is resumed from some previous model, and a function is used to
reset a parameter value, the nrounds argument in this function would be the
the number of boosting rounds in the current training.
Does not leave any attribute in the booster.