How to compare two complex numbers?

2019 8 18
0 个回答
更新时间：2019 8 18
17 次查看（30 天）

0 个投票

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 个评论
显示 2更早的评论 隐藏 2更早的评论

Matt J
Matt J 2019-8-18
Yes, it is true. What would you like r1>=r2 to mean?
Sarath S
Sarath S 2019-8-18
编辑：Sarath S 2019-8-18
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.
Bruno Luong
Bruno Luong 2019-8-18
编辑：Bruno Luong 2019-8-18
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.
Sarath S
Sarath S 2019-8-18
Okay. Thank you. I'll just go with one of the roots instead of comparing them.

请先登录，再进行评论。

请先登录，再回答此问题。

回答（0 个）

类别

在 帮助中心 和 File Exchange 中查找有关 Mathematics 的更多信息

标签

提问:

Sarath S
Sarath S
2019-8-18

编辑：

Bruno Luong
Bruno Luong
2019-8-18

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by