Precision¶
精确率Precision(也称为 positive predictive value,正预测值)是被预测为正样例中实际为正的比例。https://en.wikipedia.org/wiki/Evaluation_of_binary_classifiers 该类管理二分类任务的precision分数。
代码示例¶
import paddle.fluid as fluid
import numpy as np
metric = fluid.metrics.Precision()
# generate the preds and labels
preds = [[0.1], [0.7], [0.8], [0.9], [0.2],
[0.2], [0.3], [0.5], [0.8], [0.6]]
labels = [[0], [1], [1], [1], [1],
[0], [0], [0], [0], [0]]
preds = np.array(preds)
labels = np.array(labels)
metric.update(preds=preds, labels=labels)
numpy_precision = metric.eval()
print("expect precision: %.2f and got %.2f" % ( 3.0 / 5.0, numpy_precision))