PyTorch torch.randn() Method

PyTorch torch.randn() method “returns a tensor filled with random numbers from a normal distribution with mean 0 and variance 1.”

Syntax

torch.randn(*size, *, out=None, dtype=None, layout=torch.strided, 
            device=None, requires_grad=False, pin_memory=False)

Parameters

1. size (int…): A sequence of integers defining the shape of the output tensor.
   
2. out (Tensor, optional): It is the output tensor.
   
3. dtype (torch.dtype, optional): The desired data type of the returned tensor. Default: If none, use a global default.
   
4. layout (torch.layout, optional): The desired layout of the returned tensor. Default: torch.strided.
   
5. device (torch.device, optional): The desired device of the returned tensor. Default: If None, use the current device for the default tensor type.
   
6. requires_grad (bool, optional): If autograd should record operations on the returned tensor. Default: False.

Example 1: How to Use the torch.randn() method

import torch

rand_tensor = torch.randn(3, 3)
print(rand_tensor)

Output

tensor([[ 0.2211, 0.1781, 0.3264],
        [ 0.3594, -0.3114, -0.8456],
        [-1.6676, -0.2437, -0.3796]])

Example 2: Generating a 3D tensor

In this example, we’ll generate a 3D tensor with a shape (2, 2, 3).

import torch

rand_tensor_3d = torch.randn(2, 2, 3)
print(rand_tensor_3d)

Output

Example 3: Using dtype and device parameters

Here, we’ll generate a tensor of shape (4, 4) with data type as torch.float64 (double precision) and place it on the cuda device (assuming you have a GPU).

import torch

# Check if CUDA is available, if not, use CPU
device = 'cuda' if torch.cuda.is_available() else 'cpu'

rand_tensor_double_on_cuda = torch.randn(4, 4, dtype=torch.float64, device=device)
print(rand_tensor_double_on_cuda)

Output

That’s it!

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Krunal

Krunal Lathiya is a seasoned Computer Science expert with over eight years in the tech industry. He boasts deep knowledge in Data Science and Machine Learning. Versed in Python, JavaScript, PHP, R, and Golang. Skilled in frameworks like Angular and React and platforms such as Node.js. His expertise spans both front-end and back-end development. His proficiency in the Machine Learning frameworks like PyTorch and Tensorflow is a testament to his versatility and commitment to the craft.