- A more correct statement about the integral is that the integral of sin(x) is equal to C-cos(x), where C is a constant of integration. So, the most you can hope for is that your result is different from -cos(x) by a constant amount.
- Your program is comparing dy1 to y1. It should be comparing dy1 to y2. In that case, you will find that the graphs are the same, except for a constant displacement.
How to do integral for data
1 次查看(过去 30 天)
显示 更早的评论
How can I find y, if I know dy/dx from 0 to 1 ?
Since we know the integral of sinx is -cosx, I trie to use cumtrapz, but I cannot get correct line.
Here are my code. Can I have any hints for this? Thank you.
clear all;close all;clc
dt=0.1;
x=0:dt:2*pi;
y1=sin(x);
y2=-cos(x);
figure
subplot(211)
plot(x,y1,x,y2);grid on
legend('sinx','interal : -cosx')
dy1=cumtrapz(x,y1);
subplot(212)
plot(x,y1);hold on
plot(x,dy1);grid on
title('using cumtrapz')
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/481678/image.jpeg)
0 个评论
回答(1 个)
William
2021-1-7
I have two comments:
另请参阅
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!