residue complex number by matlab
4 次查看(过去 30 天)
显示 更早的评论
how can I find the residue of (z+1)/(z^3 (z-2)) by using matlab ?
0 个评论
回答(1 个)
John D'Errico
2015-3-13
I can't recall if I ever published this tool. I thought I did.
fun = @(z) (z+1)./(z.^3.*(z-2));
format long g
We know z=2 to be a first order pole.
[res,err] = residueEst(fun,2,'poleorder',1)
res =
0.375
err =
8.8624722305483e-16
And z=0 is a 3rd order pole.
[res,err] = residueEst(fun,0,'poleorder',3)
res =
-0.187500006276744
err =
2.93992309142077e-09
Expect a wee bit less accuracy around higher order poles, but it still did reasonably well.
As I said, I thought it was posted on the File Exchange, but it may not have been. I've written so many neat toys over the years, that sometimes I forget to post them...
As it turns out, I never did post it. I'll update the limest submission to include residueEst, as they are both limit calculators.
8 个评论
John D'Errico
2015-3-16
That is good to know. Too often these tools contain nice additional abilities that we old-timers never realize were added.
Niklas Kurz
2021-7-15
编辑:Niklas Kurz
2021-7-15
what if there is an indetermined variable in the function? (fun = @(z,a)). Can it deal with two parameters?
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Environment and Settings 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!