Some Handy PyTorch Functions

I have compiled some PyTorch Functions which could come handy at times.

rsqrt()
topk()
frac()
eye()
masked-select()

Before we begin, let's install and import PyTorch

# Uncomment and run the appropriate command for your operating system, if required

# Linux / Binder
# !pip install numpy torch==1.7.0+cpu torchvision==0.8.1+cpu torchaudio==0.7.0 -f https://download.pytorch.org/whl/torch_stable.html

# Windows
# !pip install numpy torch==1.7.0+cpu torchvision==0.8.1+cpu torchaudio==0.7.0 -f https://download.pytorch.org/whl/torch_stable.html

# MacOS
# !pip install numpy torch torchvision torchaudio

# Import torch and other required modules
import torch

Function 1 - torch.rsqrt()

This function returns a tensor which contains the reciprocal of the square root of each element in the input.
It takes the input as an argument and you can also specify the output vector.

# Example 1 - working 
a = [1, 4, 9]
a = torch.Tensor(a)
torch.rsqrt(a)

tensor([1.0000, 0.5000, 0.3333])