.select()

The .select() method in PyTorch returns a specific slice of a tensor along a specified dimension, reducing the dimensionality of the output tensor by one compared to the input tensor.

Syntax

torch.select(input, dim, index)

• input: The input tensor.
• dim: The dimension along which to select.
• index: The index of the slice to select along the specified dimension.

Example

The following example illustrates the usage of .select() method:

import torch

# 2D tensor
tensor = torch.tensor([[10, 20], [30, 40], [50, 60]])
print("Input Tensor: ", tensor)

# Select a row (dim=0)
row = torch.select(tensor, 0, 1)
print("\nSelected Row (dim=0, index=1):", row)

# Select a column (dim=1)
col = torch.select(tensor, 1, 0)
print("\nSelected Column (dim=1, index=0):", col)

The above code gives the following output:

Input Tensor:  tensor([[10, 20],
        [30, 40],
        [50, 60]])

Selected Row (dim=0, index=1): tensor([30, 40])

Selected Column (dim=1, index=0): tensor([10, 30, 50])