NumPy: Test element-wise for complex number, real number of a given array. Also test whether a given number is a scalar type or not

Last update on August 28 2025 12:36:44 (UTC/GMT +8 hours)

Test for Complex/Real/Scalar

Write a NumPy program to test element-wise for complex numbers, real numbers in a given array. Also test if a given number is of a scalar type or not.

This problem involves using NumPy to perform type checks on elements of an array and individual numbers. The task is to write a program that tests each element of a given NumPy array to determine if it is a complex number or a real number. Additionally, the program should check if a given number is of a scalar type. These checks are useful for data validation and type-specific operations, ensuring that numerical data is appropriately classified before performing further computations.

Sample Solution :

Python Code :

# Importing the NumPy library with an alias 'np'
import numpy as np

# Creating a NumPy array 'a' containing various types of numbers (complex, real, scalar)
a = np.array([1+1j, 1+0j, 4.5, 3, 2, 2j])

# Printing the original array 'a'
print("Original array")
print(a)

# Checking the given array 'a' element-wise for complex numbers and printing the result
print("Checking for complex number:")
print(np.iscomplex(a))

# Checking the given array 'a' element-wise for real numbers and printing the result
print("Checking for real number:")
print(np.isreal(a))

# Checking if a value is a scalar or not (in this case, checking if 3.1 is a scalar)
print("Checking for scalar type:")
print(np.isscalar(3.1))

# Checking if a list ([3.1]) is a scalar or not (in this case, it's not a scalar)
print(np.isscalar([3.1])) 

Output:

Original array
[ 1.0+1.j  1.0+0.j  4.5+0.j  3.0+0.j  2.0+0.j  0.0+2.j]
Checking for complex number:
[ True False False False False  True]
Checking for real number:
[False  True  True  True  True False]
Checking for scalar type:
True
False                         

Explanation:

In the above exercise -

np.array([1+1j, 1+0j, 4.5, 3, 2, 2j]) creates a NumPy array 'a' with a mix of complex and real numbers.

print(np.isreal(a)): Here np.isreal() function tests element-wise if the values in the array 'a' are real numbers. The function returns a boolean array of the same shape as 'a', with True for real values and False for complex values

print(np.isscalar(3.1)): Here np.isscalar() function checks if the given object (3.1) is a scalar. In this case, 3.1 is a scalar (a single number), so the function returns True.

print(np.isscalar([3.1])): Here np.isscalar() function checks if the given object ([3.1]) is a scalar. In this case, [3.1] is a list containing a single number, but it is not a scalar, so the function returns False.

Visual Presentation:

For more Practice: Solve these Related Problems:

• Identify which elements of an array are complex numbers using np.iscomplex.
• Verify if a given multi-dimensional array consists solely of real numbers.
• Differently handle scalar and array inputs by testing with np.isscalar.
• Write a function that separates complex and real parts of an array into two arrays.

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