Accuracy
- class
paddle.fluid.metrics.
Accuracy
(name=None)[源代码]
该接口用来计算多个mini-batch的平均准确率。Accuracy对象有两个状态value和weight。Accuracy的定义参照 https://en.wikipedia.org/wiki/Accuracy_and_precision 。
- 参数:
- name (str,可选) – 具体用法请参见 Name ,一般无需设置,默认值为None。
返回:初始化后的 Accuracy
对象
返回类型:Accuracy
代码示例
- import paddle.fluid as fluid
- # 假设有batch_size = 128
- batch_size=128
- accuracy_manager = fluid.metrics.Accuracy()
- # 假设第一个batch的准确率为0.9
- batch1_acc = 0.9
- accuracy_manager.update(value = batch1_acc, weight = batch_size)
- print("expect accuracy: %.2f, get accuracy: %.2f" % (batch1_acc, accuracy_manager.eval()))
- # 假设第二个batch的准确率为0.8
- batch2_acc = 0.8
- accuracy_manager.update(value = batch2_acc, weight = batch_size)
- #batch1和batch2的联合准确率为(batch1_acc * batch_size + batch2_acc * batch_size) / batch_size / 2
- print("expect accuracy: %.2f, get accuracy: %.2f" % ((batch1_acc * batch_size + batch2_acc * batch_size) / batch_size / 2, accuracy_manager.eval()))
- #重置accuracy_manager
- accuracy_manager.reset()
- #假设第三个batch的准确率为0.8
- batch3_acc = 0.8
- accuracy_manager.update(value = batch3_acc, weight = batch_size)
- print("expect accuracy: %.2f, get accuracy: %.2f" % (batch3_acc, accuracy_manager.eval()))
update
(value, weight)
该函数使用输入的(value, weight)来累计更新Accuracy对象的对应状态,更新方式如下:
- 参数:
- value (float|numpy.array) – mini-batch的正确率
- weight (int|float) – mini-batch的大小
返回:无
eval
()
该函数计算并返回累计的mini-batches的平均准确率。
返回:累计的mini-batches的平均准确率
返回类型:float或numpy.array