Order of roots obtained from function roots
2 次查看(过去 30 天)
显示 更早的评论
Dear all,
I have a funny problem. I have a third-degree polynomial f(s1) which depends on a variable 'm'. When I vary 'm', at some points, the ROOTS function returns me a different order of roots. For example,
when m=217:
s1 =
2.241355481895662 - 1.756029299682315i
1.921143944919372 + 1.773701622048629i
0.215633777118811 - 0.917762110838706i
when m=218;
s1 =
1.918712404828970 + 1.767930620926665i
2.241124388076128 - 1.749637415502876i
0.222483229595857 - 0.896179899600968i
So, do you know how to solve that problem? Thanks Best
0 个评论
采纳的回答
John D'Errico
2018-6-14
Roots does not assure any specific order of the returned roots, nor should it rationally do so.
Feel free to sort them in any order you desire. However, you need to recognize there is no natural ordering of a set of complex numbers. Should they be sorted in terms of increasing real part? Imaginary part? Magnitude? Angle in the complex plane?
更多回答(0 个)
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Shifting and Sorting Matrices 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!