LogLoss
LogLoss
- class LogLoss(multioutput='uniform_average', multivariate=False)[source]
Logarithmic loss for distributional predictions.
For a predictive distribution \(d\) with pdf \(p_d\) and a ground truth value \(y\), the logarithmic loss is defined as \(L(y, d) := -\log p_d(y)\).
evaluatecomputes the average test sample loss.evaluate_by_indexproduces the loss sample by test data point.multivariatecontrols averaging over variables.
- Parameters:
- multioutput‘uniform_average’ (default), 1D array-like, or ‘raw_values’
Whether and how to aggregate metric for multivariate (multioutput) data.
If
'uniform_average'(default), errors of all outputs are averaged with uniform weight.If 1D array-like, errors are averaged across variables, with values used as averaging weights (same order).
If
'raw_values', does not average across variables (outputs), per-variable errors are returned.
- multivariatebool, optional, default=False
if True, behaves as multivariate log-loss: the log-loss is computed for entire row, results one score per row
if False, is univariate log-loss: the log-loss is computed per variable marginal, results in many scores per row
Methods
__call__(y_true, y_pred, **kwargs)Calculate metric value using underlying metric function.
- __call__(y_true, y_pred, **kwargs)[source]
Calculate metric value using underlying metric function.
- Parameters:
- y_truepd.Series, pd.DataFrame or np.array of shape (fh,) or (fh, n_outputs) where fh is the forecasting horizon
Ground truth (correct) target values.
- y_predreturn object of probabilistic prediction method scitype:y_pred
must be at fh and for variables equal to those in y_true.
- Returns:
- lossfloat or 1-column pd.DataFrame with calculated metric value(s)
metric is always averaged (arithmetic) over fh values if multioutput = “raw_values”,
will have a column level corresponding to variables in y_true
- if multioutput = multioutput = “uniform_average” or or array-like
entries will be averaged over output variable column
- if score_average = False,
will have column levels corresponding to quantiles/intervals
- if score_average = True,
entries will be averaged over quantiles/interval column

