how to pass event_level and verbose control parameters to tune_grid() via control_stack_grid()?

Machine Learning and Modeling
,
1

Hi: I've been enjoying tidymodels, but now trying to combine several different models via stacks: all looks good except that when I call tune_grid() I get an error from my existing parameter control = control_grid(event_level = 'second', verbose = TRUE) and instead (per the docs) I have to pass in control = control_stack_grid(). But now I don't know how to specify the event_level or verbosity. Can anyone help?

For clarity, here's the pre-stack code for a single model:

    tm.workflow %>%
        tune_grid(resamples = tm.samples,
                  grid = tm.grid,
                  metrics = metric_set(accuracy, bal_accuracy, roc_auc, kap),
                  control = control_grid(event_level = 'second', verbose = TRUE))

and here's the code for a model that's going to be included in a stack:

    tm.workflow %>%
        tune_grid(resamples = tm.samples,
                  grid = tm.grid,
                  metrics = metric_set(accuracy, bal_accuracy, roc_auc, kap),
                  control = control_stack_grid())     # how do I pass in event_level and verbose?

Thanks!

Mike

2

It looks like a bug. I would add an issue to the GitHub repo.

3

Oh, I'm an idiot: I just realised I wasn't interpreting the description in the docs (Control wrappers — control_stack_grid • stacks) correctly; it turns out I don't have to call control_stack_grid(): I just have to append save_pred = TRUE and save_workflow = TRUE to my existing call to control_grid(): this actually works:

    tm.workflow %>%
        tune_grid(resamples = tm.samples,
                  grid = tm.grid,
                  metrics = metric_set(accuracy, bal_accuracy, roc_auc, kap),
                  control = control_grid(event_level = 'second', verbose = TRUE,
                                         save_pred = TRUE, save_workflow = TRUE))

I guess the docs are not quite as clear as they could be (for me, at first glance, at any rate!), but no bug as such. I'll close this.