Complex numbers in python
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Music by Eric Matyas
https://www.soundimage.org
Track title: Riding Sky Waves v001
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Chapters
00:00 Question
00:18 Accepted answer (Score 250)
01:21 Answer 2 (Score 17)
01:56 Answer 3 (Score 0)
02:46 Thank you
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Full question
https://stackoverflow.com/questions/8370...
Accepted answer links:
[Reasoning found here.]: https://stackoverflow.com/q/24812444/775...
[The type of a complex number is ]: https://docs.python.org/2/library/stdtyp...
[The standard module ]: http://docs.python.org/library/cmath.htm...
Answer 2 links:
[complex numbers]: http://docs.python.org/library/stdtypes....
Answer 3 links:
[complex]: https://docs.python.org/3/library/functi...
[int]: https://docs.python.org/3/library/functi...
[float]: https://docs.python.org/3/library/functi...
[complex]: https://docs.python.org/3/library/functi...
[int]: https://docs.python.org/2.7/library/func...
[long]: https://docs.python.org/2.7/library/func...
[float]: https://docs.python.org/2.7/library/func...
[complex]: https://docs.python.org/2.7/library/func...
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Content licensed under CC BY-SA
https://meta.stackexchange.com/help/lice...
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Tags
#python #types #complexnumbers
#avk47
ACCEPTED ANSWER
Score 263
In python, you can put ‘j’ or ‘J’ after a number to make it imaginary, so you can write complex literals easily:
>>> 1j
1j
>>> 1J
1j
>>> 1j * 1j
(-1+0j)
The ‘j’ suffix comes from electrical engineering, where the variable ‘i’ is usually used for current. (Reasoning found here.)
The type of a complex number is complex, and you can use the type as a constructor if you prefer:
>>> complex(2,3)
(2+3j)
A complex number has some built-in accessors:
>>> z = 2+3j
>>> z.real
2.0
>>> z.imag
3.0
>>> z.conjugate()
(2-3j)
Several built-in functions support complex numbers:
>>> abs(3 + 4j)
5.0
>>> pow(3 + 4j, 2)
(-7+24j)
The standard module cmath has more functions that handle complex numbers:
>>> import cmath
>>> cmath.sin(2 + 3j)
(9.15449914691143-4.168906959966565j)
ANSWER 2
Score 19
The following example for complex numbers should be self explanatory including the error message at the end
>>> x=complex(1,2)
>>> print x
(1+2j)
>>> y=complex(3,4)
>>> print y
(3+4j)
>>> z=x+y
>>> print x
(1+2j)
>>> print z
(4+6j)
>>> z=x*y
>>> print z
(-5+10j)
>>> z=x/y
>>> print z
(0.44+0.08j)
>>> print x.conjugate()
(1-2j)
>>> print x.imag
2.0
>>> print x.real
1.0
>>> print x>y
Traceback (most recent call last):
File "<pyshell#149>", line 1, in <module>
print x>y
TypeError: no ordering relation is defined for complex numbers
>>> print x==y
False
>>>
ANSWER 3
Score 0
Yes, complex type is supported in Python.
For numbers, Python 3 supports 3 types int, float and complex types as shown below:
print(type(100), isinstance(100, int))
print(type(100.23), isinstance(100.23, float))
print(type(100 + 2j), isinstance(100 + 2j, complex))
Output:
<class 'int'> True
<class 'float'> True
<class 'complex'> True
For numbers, Python 2 supperts 4 types int, long, float and complex types as shown below:
print(type(100), isinstance(100, int))
print(type(10000000000000000000), isinstance(10000000000000000000, long))
print(type(100.23), isinstance(100.23, float))
print(type(100 + 2j), isinstance(100 + 2j, complex))
Output:
(<type 'int'>, True)
(<type 'long'>, True)
(<type 'float'>, True)
(<type 'complex'>, True)