# Python NumPy – Return real parts if input is complex with all imaginary parts close to zero

• Last Updated : 01 May, 2022

In this article, we will discuss how to return real parts if the input is complex with all imaginary parts close to zero in Python.

The numpy np.real_if_close() method is used to return the real parts if the input is a complex number with all imaginary parts close to zero. “Close to zero” is defined as tol * (machine epsilon of the type for a).

syntax: numpy.real_if_close(a, tol=100)

parameters:

• a: array like object. input array.
• tot: Machine epsilons tolerance for the complex component of the array’s elements.

returns:

out: The type of an is utilized for the output if an is true. The returning type is float if has complex elements.

### Example 1:

In this example, the NumPy package is imported. An array is created using numpy.array() method which contains complex numbers where the imaginary parts are near 0 and np.real_if_close() returns the real parts. The shape, datatype, and dimensions of the array can be found by .shape, .dtype, and .ndim attributes.

## Python3

 `import` `numpy as np`` ` `# Creating an array``array ``=` `np.array([``1``,``2``+``3.e``-``18j``,``-``3``+``4.e``-``14j``])``print``(array)`` ` `# shape of the array is``print``(``"Shape of the array is : "``,array.shape)`` ` `# dimension of the array``print``(``"The dimension of the array is : "``,array.ndim)`` ` `# Datatype of the array``print``(``"Datatype of our Array is : "``,array.dtype)`` ` `# returning real part``print``(np.real_if_close(array, tol``=` `1000``))`

Output:

```[ 1.+0.e+00j  2.+3.e-18j -3.+4.e-14j]
Shape of the array is :  (3,)
The dimension of the array is :  1
Datatype of our Array is :  complex128
[ 1.  2. -3.]```

### Example 2:

In this case, imaginary numbers are not close to zero so the same array is returned back.

## Python3

 `import` `numpy as np`` ` `# Creating an array``array ``=` `np.array([``1``+``5j``,``3``-``6j``])``print``(array)`` ` `# shape of the array is``print``(``"Shape of the array is : "``,array.shape)`` ` `# dimension of the array``print``(``"The dimension of the array is : "``,array.ndim)`` ` `# Datatype of the array``print``(``"Datatype of our Array is : "``,array.dtype)`` ` `# returning real part``print``(np.real_if_close(array, tol``=` `1000``))`

Output:

```[1.+5.j 3.-6.j]
Shape of the array is :  (2,)
The dimension of the array is :  1
Datatype of our Array is :  complex128
[1.+5.j 3.-6.j]```

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