How to compare two complex numbers?

I am trying to implement Muller's method for computing the complex root of a polynomial.
Here r1,r2 could be complex in nature.
How do i compare r1 and r2. r1 >= r2 doesnt seem to be working. I have read elsewhere that > operator compares only the real part of the complex number. Is this true?

4 Comments

Yes, it is true. What would you like r1>=r2 to mean?
Sarath S
Sarath S on 18 Aug 2019
Edited: Sarath S on 18 Aug 2019
i would like it to return 1 if r1 is geater than or equal to r2.
ex. if r1 = 4 + 3i and r2 = 3 + 5i, then return 0 because |r1| < |r2|.
I thought that > would compare the magnitudes if it deals with complex numbers.
But i do realise that comparing two complex numbers doesnt make much sense.
Then use
abs(r1) < abs(r2)
You notice this is NOT the same than r1 < r2 even for real numbers.
If you apply the first definition with r1=-4 and r2=2 it returns FALSE, which is kind of not comfortable to believe.
In fact there is no order relation for complex numbers.
TMW decides to implement a order relation on complex field that is extended from real number ordering, but rarely pertinent for application.
Okay. Thank you. I'll just go with one of the roots instead of comparing them.

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on 18 Aug 2019

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on 18 Aug 2019

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