交叉熵损失函数报错

Handsome_zhou

IndexError: Target 3 is out of bounds.

原因：交叉熵损失函数的输入矩阵元素大小不能超过2.

import torch
import torch.nn as nn
a = torch.tensor([[0.7,0.2,0.1]])
b = torch.tensor([2])
loss = nn.CrossEntropyLoss()
l = loss(a, b)
print(l)