Pytorch学习笔记【5】---tensor的拼接和拆分
Pytorch学习笔记【5】—tensor的拼接和拆分
Pytorch笔记目录：点击进入
文章目录
- Pytorch学习笔记【5】---tensor的拼接和拆分
- 1.cat
- 2.stack
- 3.根据长度来分割
- 4.通过通道数来分割
1.cat
把两个向量纵向拼接起来，并不会增加新的维度
# cat
a = torch.rand(4,32,8)
b = torch.rand(5,32,8)
print(torch.cat([a,b],dim=0).shape)
out：
torch.Size([9, 32, 8])
a1 =torch.rand(4,3,32,32)
a2 = torch.rand(5,3,32,32)
print(torch.cat([a1,a2],dim=0).shape)
a2 = torch.rand(4,1,32,32)
print(torch.cat([a1,a2],dim=1).shape)
out:
torch.Size([9, 3, 32, 32])
torch.Size([4, 4, 32, 32])
2.stack
把两个tensor横向连接起来，会增加一个新的维度
# stack create new dim
a1 = torch.rand(4,3,16,32)
a2 = torch.rand(4,3,16,32)
print(torch.stack([a1,a2],dim=2).shape)
out:
torch.Size([4, 3, 2, 16, 32])
3.根据长度来分割
# Split by len
a = torch.rand(32,8)
b = torch.rand(32,8)
c = torch.stack([a,b],dim=0)
print(c.shape)
aa,bb = c.split([1,1],dim=0)
print(aa.shape,bb.shape)
out:
torch.Size([2, 32, 8])
torch.Size([1, 32, 8]) torch.Size([1, 32, 8])
4.通过通道数来分割
# Split by num
aa,bb = c.chunk(2,dim=0)
print(aa.shape,bb.shape)
out:
torch.Size([1, 32, 8]) torch.Size([1, 32, 8])