# .sin()

Published Jun 25, 2024
Contribute to Docs

In NumPy, the `.sin()` method calculates the trigonometric sine of each element in an array. This method operates element-wise on an array and returns a new array containing the sine values of the input array’s elements. It is beneficial in mathematical computations involving trigonometric operations.

## Syntax

``````numpy.sin(x, out=None, where=True)
``````
• `array`: An array-like structure containing the elements for which the sine is computed. The elements should be in radians, not degrees.
• `out` (Optional): Specifies the array where the result of the operation should be stored. If not provided, a new array is created to store the results.
• `where` (Optional): The condition (array of boolean values) that determines the elements where the sine function is applied.
• If the condition is `True` for a particular element, the sine is computed for that element.
• If the condition is `False` for a particular element, the sine of the element will not be computed and the original element is retained.
• If not provided, the sine is computed for all elements.

## Example

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

```# Importing the 'numpy' library as 'np'import numpy as np
# When the elements in the array are already in radiansarray1 = np.array([0, np.pi/2, np.pi, 3*np.pi/2])result1 = np.sin(array1)
# The angles are originally in degrees, so they need to be converted to radiansarray2 = np.array((0, 30, 45, 90, 180))result2 = np.sin(array2 * np.pi/180) # convert to radians
# using the where parameterarray3 = np.array([np.pi/6, np.pi/4, np.pi/2, np.pi])result3 = np.sin(array3, where=array3 >= np.pi/2)
print(result1)print(result2)print(result3)
```

The output of the above code is as shown below:

```[ 0.0000000e+00  1.0000000e+00  1.2246468e-16 -1.0000000e+00][0.00000000e+00 5.00000000e-01 7.07106781e-01 1.00000000e+00 1.22464680e-16][0.0000000e+00 0.0000000e+00 1.0000000e+00 1.2246468e-16]
```

## Codebyte Example

In this codebyte example, the `.sin()` method computes the sine of the elements of the array:

`usVisit uscodeHide codeCodeOutputHide outputHide outputLoading...`