I to create a function using besselj function and solve it using fzero to find eigenvalues like this...

12 次查看（过去 30 天）
N/A
N/A 2015-6-3
评论： N/A 2015-6-3
t = 1:.01:30;
x = t;
y = besselj(1,t);
t = 1:.01:30;
b = 10;
y2 = besselj(0,t);
x0=[0 30];
fun = t.*y - b.*y2 ;
z = fzero(fun, x0)
  1 个评论
N/A
N/A 2015-6-3
Whe I try to put this code at the MatLab it shows this message: Error using fzero (line 169) FUN must be a function, a valid string expression, or an inline function object.
Error in Try6 (line 9) z = fzero(fun, x0)

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Walter Roberson
Walter Roberson 2015-6-3
Symbolically you seem to be trying to solve
t * BesselJ(1,t) - 10 * BesselJ(0,t)
probably for t. If that is the case, then code
fzero(@(t) t .* besselj(1,t) - 10 * besselj(0,t), x0)
Note: there are 10 zeros between 0 and 30, and fzero does not promise to find the first. It might refuse to find any because the expression is negative at both 0 and 30 and so fzero would not know that there is a zero crossing.
  5 个评论
显示 3更早的评论
N/A
N/A 2015-6-3
Thanks a lot!! But I also used this code: a = 0:30; for x0 = 1:length(a) t = 1:.01:10; z = x0; z = fzero(@(t) t .* besselj(1,t) - 10 * besselj(0,t), x0) end
with the above code I found all the values that I want. But some values show up more than once. Do you know how to do it to they show up only once?

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Number Theory 的更多信息

标签

Community Treasure Hunt

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

Start Hunting!

Translated by