Complex number in python

Question

How to write a complex number in python? Indeed I have:

import math
a=3
b=4
function=a*j*x+b*y

I don't want to write directly 3j in my function since I absolutely want to use a, so how to convert a into a complex number? Cause in matlab it works when printing :

a=3
b=a*i

The result will gave: 0 + 3.0000i

Thank you for your answers.

If you want to use `j` as a complex number, you need `1j`. – user2357112 Feb 05 '14 at 09:34 — user2357112, Feb 05 '14 at 09:34

score 6 · Accepted Answer · answered Feb 05 '14 at 09:35

6

j alone is a variable, you can have the complex number by typing 1j

>>> type(j)
NameError: name 'j' is not defined
>>> type(1j)
<type 'complex'>

So your code can be written as a function as

def function(x, y):
    a = 3
    b = 4
    return a*1j*x+b*y

answered Feb 05 '14 at 09:35

Rems

4,837
3
27
24

This [helps](https://stackoverflow.com/a/73361181/1176573)! – Rajesh Swarnkar Aug 15 '22 at 12:43

Ashwini Chaudhary · Answer 2 · 2014-02-05T09:22:24.860

2

You can use the complex function to create a complex number from variables:

>>> a = 3
>>> b = 4
>>> complex(a, b)
(3+4j)

edited Feb 05 '14 at 09:22

answered Feb 05 '14 at 09:15

Ashwini Chaudhary

244,495
58
464
504

score 0 · Answer 3 · answered Feb 05 '14 at 09:22

0

You can simply use Python's Built in complex() function

>>> first_number = 10
>>> second_number = 15
>>> complex(first_number, second_number)
(10+15j)

answered Feb 05 '14 at 09:22

Maninder Singh

829
1
7
13

Complex number in python

3 Answers3

Linked