Question about bvp4c solution

2015 5 4
1 个回答
回答已采纳
更新时间：2015 5 5
8 次查看（30 天）

0 个投票

I used bvp4c to solve second order differential equation: A*y'' = f(y), now I want to get some special values from the solutions. How to get the values of y'' and y' from each point?

请先登录，再回答此问题。

 采纳的回答

Torsten
Torsten 2015-5-4

1 个投票

If you solved your equation by solving the System
y1'=y2
y2'=f(y)/A,
you can get y' and y'' by
yp=deval(sol.yp,sol.x);
plot(sol.x,yp(1,:),sol.x,yp(2,:));
Here, yp(1,:)=y' and yp(2,:)=y''.
Best wishes
Torsten.

2 个评论
显示 无 隐藏 无

Jane
Jane 2015-5-4
编辑：Jane 2015-5-4
Torsten, thank you very much for your kind help! Sorry to trouble you again, when I use:
yp=deval(sol.yp,sol.x);
it shows:
Error using deval
must be a structure returned by a differential equation solver.
Error in bvp3
yp = deval(sol.yp,sol.x);
What would be wrong with it?
Torsten
Torsten 2015-5-5
You must call deval with the solution obtained by bvp4c.
Thus
sol=bvp4c(...);
yp=deval(sol.yp,sol.x);
Best wishes
Torsten.

请先登录，再进行评论。

更多回答（0 个）

类别

在 帮助中心 和 File Exchange 中查找有关 Solver Outputs and Iterative Display 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