# How to compute the element-wise angle of the given input tensor in PyTorch?

PyTorchServer Side ProgrammingProgramming

To compute the elementwise angle of the given input tensor, we apply torch.angle(). It takes an input tensor and returns a tensor with angle in radian computed element wise. To convert the angles into the degree we multiply the angle in radian by 180/np.pi. It supports both real and complex-valued tensors.

### Syntax

torch.angle(input)

### Steps

To compute the elementwise angle, you could follow the steps given below −

• Import the required library. In all the following examples, the required Python library is torch. Make sure you have already installed it.

import torch
• Define torch tensors and print them.

input = torch.tensor([1 + 1j, -1 -4j, 3-2j])
• Compute torch.angle(input). It is a tensor with angle in radians computed elementwise for the input.

angle = torch.angle(input)
• Print the above computed tensor with angles in radians.

print("Angles in Radian:\n", angle)

Let's take a couple of examples to demonstrate how to compute elementwise angles in radians and degrees.

## Example 1

In the Python3 program below we compute element wise angle in radians and degrees of the given input tensor.

# Python 3 program to compute the element-wise
# angle (in radians and degree) of the given input tensor
# Import the required libraries
import torch
from numpy import pi

# define a complex input tensor
input = torch.tensor([1 + 1j, -1 -4j, 3-2j])

# print the input tensor
print("Input Tensor:\n", input)

# compute the angle in radians
angle = torch.angle(input)

# print the computed tensor of angles

# convert the angle s in degree
degree = angle*180/pi

# print the computed tensor of degree
print("Angles in Degree:\n", degree)

## Output

Input Tensor:
tensor([ 1.+1.j, -1.-4.j, 3.-2.j])
tensor([ 0.7854, -1.8158, -0.5880])
Angles in Degree:
tensor([ 45.0000, -104.0362, -33.6901])

## Example 2

In this program, we compute element wise angle in radians and degrees of the given input tensor.

# Python 3 program to to compute the element-wise
# angle (in radians and degrees) of the given input tensor
# Import the required libraries
import torch
from numpy import pi

# define a complex input tensor
real = torch.randn(3,4)
imag = torch.randn(3,4)
input = torch.complex(real, imag)

# print the input tensor
print("Input Tensor:\n", input)

# compute the angle in radians
angle = torch.angle(input)

# print the computed tensor of angles

# convert the angle s in degree
degree = angle*180/pi

# print the computed tensor of degree
print("Angles in Degree:\n", degree)

## Output

Input Tensor:
tensor([[ 0.1967-0.0188j, -0.5311-1.2427j, 0.9937+0.0051j, - 1.8304-0.1321j],
[-0.1787+1.7834j, 0.9925+0.2452j, -0.8813-0.0207j, - 0.4967+0.9938j],
[-0.9051-0.1204j, 1.0013+0.3430j, 0.6131-0.0317j, - 0.3861+0.6365j]])
[-172.4209, 18.9103, -2.9624, 121.2437]])