why results from trapz cumtrapz and integral are so different

2 次查看（过去 30 天）

显示更早的评论

Meva 2015-4-7

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/196484-why-results-from-trapz-cumtrapz-and-integral-are-so-different

评论： Meva 2015-4-7

在 MATLAB Online 中打开

Hi,

I need to integrate numerically 21 functions, some of them are

int_0^x (...) % integrate from zero to x

some of them

int_0^x (int_0^x (...))     % integrate from zero to x 
                              then again integrate from 0 to x

some of them

int_0^1( int_0^x (int_0^x (...)))   % integrate from zero to one and then   
                                      integrate from zero to x 
                                      then again integrate from 0 to x

I have two codes. First one uses cumtrapz for

int_0^x

and trapz for

int_0^1 ( ...

Second one uses integral method (with function handle) for all the integrals above.

The results are amazing! They are very different like ten times bigger or smaller from each other.

Which method is trusted?

4 个评论
显示 2更早的评论隐藏 2更早的评论

Meva 2015-4-7

april_7.m

and this is the integral method code.

Meva 2015-4-7

the results might be with different parameters but they are very different as I checked

请先登录，再进行评论。

请先登录，再回答此问题。

回答（0 个）

请先登录，再回答此问题。

类别

MATLAB Mathematics Numerical Integration and Differential Equations Numerical Integration and Differentiation

在 Help Center 和 File Exchange 中查找有关 Numerical Integration and Differentiation 的更多信息

Community Treasure Hunt

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

Start Hunting!

Translated by