plot_timeline

optuna.visualization.plot_timeline(study, n_recent_trials=None)

Plot the timeline of a study.

Parameters:

• study (Study) – A Study object whose trials are plotted with their lifetime.

• n_recent_trials (int | None) – The number of recent trials to plot. If None, all trials are plotted. If specified, only the most recent n_recent_trials will be displayed. Must be a positive integer.

Returns:

A plotly.graph_objects.Figure object.

Raises:

ValueError – if n_recent_trials is 0 or negative.

Return type:

Figure

The following code snippet shows how to plot the timeline of a study. Timeline plot can visualize trials with overlapping execution time (e.g., in distributed environments).

import time

import optuna
from plotly.io import show


def objective(trial):
    x = trial.suggest_float("x", 0, 1)
    time.sleep(x * 0.1)
    if x > 0.8:
        raise ValueError()
    if x > 0.4:
        raise optuna.TrialPruned()
    return x ** 2


study = optuna.create_study(direction="minimize")
study.optimize(
    objective, n_trials=50, n_jobs=2, catch=(ValueError,)
)

fig = optuna.visualization.plot_timeline(study)
show(fig)