就是抽样

a = torch.FloatTensor([[0,0,0,0,0,0,0,100]])
b=softmax(a)
b.multinomial()

Variable containing:
7
[torch.LongTensor of size 1x1]

b.multinomial()

Variable containing:
7
[torch.LongTensor of size 1x1]

b.multinomial()

Variable containing:
7
[torch.LongTensor of size 1x1]

b.multinomial()

Variable containing:
7
[torch.LongTensor of size 1x1]

可见是按b的值也就是概率选的