NumPy sqrt() in Python – Tutorial
Python NumPy module is used to work with multidimensional arrays and matrix manipulations. We can use NumPy sqrt() function to get the square root of the matrix elements.
Python NumPy sqrt() Example
import numpy
array_2d = numpy.array([[1, 4], [9, 16]], dtype=numpy.float)
print(array_2d)
array_2d_sqrt = numpy.sqrt(array_2d)
print(array_2d_sqrt)
Output:
[[ 1. 4.]
[ 9. 16.]]
[[1. 2.]
[3. 4.]]
Let’s look at another example where the matrix elements are not square of integers. This time we will use the Python interpreter.
>>> import numpy
>>>
>>> array = numpy.array([[1, 3], [5, 7]], dtype=numpy.float)
>>>
>>> print(array)
[[1. 3.]
[5. 7.]]
>>>
>>> array_sqrt = numpy.sqrt(array)
>>>
>>> print(array_sqrt)
[[1. 1.73205081]
[2.23606798 2.64575131]]
>>>
NumPy sqrt() Infinity Example
Let’s see what happens when we have infinity as the matrix element.
>>> array = numpy.array([1, numpy.inf])
>>>
>>> numpy.sqrt(array)
array([ 1., inf])
>>>
Complex Numbers
>>> array = numpy.array([1 + 2j, -3 + 4j], dtype=numpy.complex)
>>>
>>> numpy.sqrt(array)
array([1.27201965+0.78615138j, 1. +2.j ])
>>>
Negative Numbers
>>> array = numpy.array([4, -4])
>>>
>>> numpy.sqrt(array)
__main__:1: RuntimeWarning: invalid value encountered in sqrt
array([ 2., nan])
>>>
The square root of a matrix with negative numbers will throw RuntimeWarning and the square root of the element is returned as nan.
