BOHB

https://www.automl.org/blog-2nd-automl-challenge/

def BO_search_alg(space):
    bayes_algo = \
        TuneBOHB(metric="mean_accuracy", mode="max")

    # Obtain a trial dataframe from all run trials of this `tune.run` call.

    BO_anno = "BO Search Algorithm"
    analysis = tune.run(train_mnist,
                        config=space,
                        search_alg=bayes_algo,
                        num_samples=20)

    dfs = analysis.trial_dataframes
    plot(dfs, BO_anno)
    bt_model = best_model(analysis)

    return bt_model

def BOHB_search_alg(space):
    algo = \
        TuneBOHB(metric="mean_accuracy", mode="max")
    bohb = HyperBandForBOHB(
        time_attr="training_iteration",
        metric="mean_accuracy",
        mode='max',
        # Same as eta.
        reduction_factor=3,  # budgets 개수(4개 남을 때까지 반감기)
        max_t=81  # trial 당 max time
    )
    # Obtain a trial dataframe from all run trials of this `tune.run` call.

    BOHB_anno = "BOHB Search Algorithm"
    analysis = tune.run(train_mnist,
                        config=space,
                        scheduler=bohb,
                        search_alg=algo,
                        num_samples=20)

    dfs = analysis.trial_dataframes
    plot(dfs, BOHB_anno)
    bt_model = best_model(analysis)

    return bt_model