simulated annealing restarting at the wrong iteration

[topepo]

For this example, the restart was set to 10 iterations but it restarts at iteration 8:

ctrl_sa <- control_sim_anneal(verbose = TRUE, no_improve = 10L)

set.seed(1234)

svm_sa <-
  svm_wflow %>%
  tune_sim_anneal(
    resamples = penguins_folds,
    metrics = roc_res,
    initial = svm_initial,
    param_info = svm_param,
    iter = 50,
    control = ctrl_sa
  )

## Optimizing roc_auc

## Initial best: 0.84948
##  1 ◯ accept suboptimal  roc_auc=0.57004	(+/-0.172)
##  2 ◯ accept suboptimal  roc_auc=0.57004	(+/-0.172)
##  3 ◯ accept suboptimal  roc_auc=0.56876	(+/-0.1715)
##  4 ◯ accept suboptimal  roc_auc=0.56876	(+/-0.1715)
##  5 ◯ accept suboptimal  roc_auc=0.56876	(+/-0.1715)
##  6 + better suboptimal  roc_auc=0.56942	(+/-0.1715)
##  7 ◯ accept suboptimal  roc_auc=0.56848	(+/-0.1718)
##  8 ✖ restart from best  roc_auc=0.56876	(+/-0.1715)
##  9 ◯ accept suboptimal  roc_auc=0.84948	(+/-0.01685)
## 10 ◯ accept suboptimal  roc_auc=0.84948	(+/-0.01685)

Also, for some other reason, the initial grid gives different ROC results each run. This might be due to the Platt scaling used by kernlab; its CV doesn't use a controllable seed. However, we don't see this in the book example.