utils.py源码

from __future__ import division, absolute_import

__all__ = ['AverageMeter']


[docs]class AverageMeter(object):
    """Computes and stores the average and current value.

    Examples::
        >>> # Initialize a meter to record loss
        >>> losses = AverageMeter()
        >>> # Update meter after every minibatch update
        >>> losses.update(loss_value, batch_size)
    """

    def __init__(self):
        self.reset()

    def reset(self):
        self.val = 0
        self.avg = 0
        self.sum = 0
        self.count = 0

    def update(self, val, n=1):
        self.val = val
        self.sum += val * n
        self.count += n
        self.avg = self.sum / self.count

在pytorch中用utils包来更新得分、损失等等，百度根本搜不到，不行就google！！！
代码说的例子是输入有两个参数，一个是用来处理的数值，比如损失等等，另一个是批量大小。
比如损失，假设批次为32，那么每个batch_size更新一次。

代码解释说明：

losses = AverageMeter()
loss_list = [0.5,0.4,0.5,0.6,1]
batch_size = 2
for los in loss_list:
    losses.update(los,batch_size)
    print(losses.avg)

本质上还是对所有batch_size的损失取平均。