1,(a==b).sum()
import torch
a = torch.tensor([2,3,3,4])
b = torch.tensor([2,2,3,5])
c = torch.tensor([1,2,3])
print(a == b) #返回:tensor([1, 0, 1, 0], dtype=torch.uint8)
print((a==b).sum().item()) #返回:2
print(c.sum().item()) #返回:6,即c中所有元素之和
2,torch.max()
import torch
a = torch.randn(3,4)
print(a)
print(torch.max(a,1)) #返回:a中每一行的最大值,及最大值的列索引
print(torch.max(a,0)) #返回:a中每一列的最大值,及最大值的行索引
value, index = torch.max(a,1) #返回的第一个值是矩阵中元素,返回的第二个值是索引值
3,size(0)
import torch
a = torch.tensor([1,2,3,4])
b = torch.randn(3,32,32)
print(a.size()) #返回:torch.Size([4])
print(a.size(0)) #返回:4,方便标量之间的加减运算
print(b.size()) #返回:torch.Size([3,32,32])
print(b.size(0)) #返回:3
print(b.size(1)) #返回:32