sklearn.metrics.mean_poisson_deviance¶
- 
sklearn.metrics.mean_poisson_deviance(y_true, y_pred, *, sample_weight=None)[source]¶ Mean Poisson deviance regression loss.
Poisson deviance is equivalent to the Tweedie deviance with the power parameter
power=1.Read more in the User Guide.
- Parameters
 - y_truearray-like of shape (n_samples,)
 Ground truth (correct) target values. Requires y_true >= 0.
- y_predarray-like of shape (n_samples,)
 Estimated target values. Requires y_pred > 0.
- sample_weightarray-like of shape (n_samples,), default=None
 Sample weights.
- Returns
 - lossfloat
 A non-negative floating point value (the best value is 0.0).
Examples
>>> from sklearn.metrics import mean_poisson_deviance >>> y_true = [2, 0, 1, 4] >>> y_pred = [0.5, 0.5, 2., 2.] >>> mean_poisson_deviance(y_true, y_pred) 1.4260...