how to find area under the curve with cumsum and cumtrapz?

22 次查看（过去 30 天）
Swati Umamaheshwaran
评论： Swati Umamaheshwaran 2017-11-10
Please help. I am trying to find the area under the curve by using cumsum and cumtrapz but I am getting the wrong answer. I think there is an issue with the syntax of the input function and I am unable to figure it out.

请先登录，再回答此问题。

采纳的回答

John D'Errico
John D'Errico 2017-11-10
You should understand that a simple sum is not an integral. To approximate an integral using a Riemann sum, you also need to multiply by the interval. Thus, the area inside a rectangle is the product of the height and the width of the rectangle. If all you do is form the sum, you are just adding up the heights of those rectangles.
So I would predict, since the width of those rectangles is 0.01, that the cumsum would be off by a factor of roughly 100. I think that prediction comes pretty darn close.

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Special Values 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