NumPy arctan()

The numpy.arctan() method computes the arctangent (inverse tangent) of an array.

Example

import numpy as np

# create an array 
array1 = np.array([0, 1, -1])

# calculates the element-wise arctangent (inverse tangent) of array1 result = np.arctan(array1)
print(result) # Output: [ 0. 0.78539816 -0.78539816]

arctan() Syntax

The syntax of the numpy.arctan() method is:

numpy.arctan(x, out = None, where = True, dtype = None)

arctan() Arguments

The numpy.arctan() method takes the following arguments:

  • x - an input array
  • out (optional) - the output array where the result will be stored
  • where (optional) - a boolean array or condition indicating where to compute the arctangent
  • dtype (optional) - data type of the output array

arctan() Return Value

The numpy.arctan() method returns an array with the corresponding inverse tangent values.


Example 1: Use of out and where in arctan()

import numpy as np

array1 = np.array([0, -1, 1, 10, 100, -2])

# create an array of zeros with the same shape as array1
result = np.zeros_like(array1, dtype=float)  

# compute inverse tangent of elements in array1 # only where the element is greater than or equal to 0 np.arctan(array1, out = result, where = (array1 >= 0))
print(result)

Output

[0.         0.         0.78539816 1.47112767 1.56079666 0.        ]

Here,

  • out = result specifies that the output of the numpy.arctan() method should be stored in the result array,
  • where = (array1 >= 0) specifies that the inverse tangent operation should only be applied to elements in array1 that are greater than or equal to 0.

Example 2: Use of dtype Argument in arctan()

import numpy as np

# create an array
values = np.array([0, 1, -1])

# calculate the inverse tangent of # each value with float data type arctans_float = np.arctan(values, dtype = float)
print("Inverse Tangent with 'float' dtype:") print(arctans_float)
# calculate the inverse tangent of # each value with complex data type arctans_complex = np.arctan(values, dtype = complex)
print("\nInverse Tangent with 'complex' dtype:") print(arctans_complex)

Output

Inverse Tangent with 'float' dtype:
[ 0.          0.78539816 -0.78539816]

Inverse Tangent with 'complex' dtype:
[ 0.        +0.j  0.78539816+0.j -0.78539816+0.j]

Here, by specifying the desired dtype, we can control the data type of the output array according to our specific requirements.

Note: To learn more about the dtype argument, please visit NumPy Data Types.

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