How to extend one tensor with another if they do not have the same size-CodePudding

a =  tensor([   [101,  103],
        [101,  1045]
    ])


b =  tensor([   [101,  777, 227],
        [101,  888, 228]
    ])

How to I get this tensor c from a and b:

c = a   b =  tensor([   [101,  103, 0],
        [101,  1045, 0],
        [101,  777, 227],
        [101,  888, 228]
        
    ])

I tried with c = torch.cat((a, b), dim=0) but does not work.

CodePudding user response：

In general you could try to pad the first tensor to the shape of the other. For this exact problem you could do that the following way:

import torch
import torch.nn.functional as F

a = torch.tensor([
    [101,  103],
    [101,  1045]
])

b = torch.tensor([
    [101,  777, 227],
    [101,  888, 228]
])


a = F.pad(a, pad=(0, b.size()[1] - a.size()[1], 0, b.size()[0] - a.size()[0]), value=0)
print(a)

This extends the first and second dimension of the a tensor with zeros to match the b tensor.

You can then concat them:

c = torch.cat((a, b), dim=0)