What is the cos function in NumPy?

In NumPy, a library of the high-level programming language Python, the cos function can be used to calculate the cos of a given angle.

The numpy library must be imported to use the cos function.

import numpy as np

Syntax

np.cos(x, /, out=None, *, where=True, casting='same_kind', order='K', dtype=None, subok=True[, signature, extobj])  = <ufunc 'cos'>

A universal function (ufunc) is a function that operates on ndarrays in an element-by-element fashion. The cos method is a universal function.

Arguments

The cos function only accepts the following arguments.

  • x: array-like structure on the contents of which the cos function will be applied.
  • out: (optional) - the function’s output is stored at this location.
  • where (optional): if set True, a universal function is calculated at this position.
  • casting (optional): enables the user to decide how the data will be cast. If set as same_kind, safe casting will take place.
  • order (optional): determines the memory layout of the output. For example, if set as K, the function reads data in the order they are written in memory.
  • dtype (optional): the data type of the array
  • subok (optional): to pass subclasses, subokmust be set as True.

Return value

Returns an ndarray that contains the cos of the value(s) passed as arguments.

If x is scalar, the return value is also scalar.

Example

The following example demonstrates how the cos function may be implemented on an array of angle values.

import numpy as np
arr = np.cos([360, 270, 180, 90, 0])
print(arr)

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