matchzoo.metrics.precision

Precision for ranking.

Module Contents

class matchzoo.metrics.precision.Precision(k:int=1, threshold:float=0.0)

Bases: matchzoo.engine.base_metric.RankingMetric

Precision metric.

ALIAS = precision
__repr__(self)
Returns:Formated string representation of the metric.
__call__(self, y_true:np.array, y_pred:np.array)

Calculate precision@k.

Example

>>> y_true = [0, 0, 0, 1]
>>> y_pred = [0.2, 0.4, 0.3, 0.1]
>>> Precision(k=1)(y_true, y_pred)
0.0
>>> Precision(k=2)(y_true, y_pred)
0.0
>>> Precision(k=4)(y_true, y_pred)
0.25
>>> Precision(k=5)(y_true, y_pred)
0.2
Parameters:
  • y_true – The ground true label of each document.
  • y_pred – The predicted scores of each document.
Returns:

Precision @ k
Raises:

ValueError: len(r) must be >= k.