difference between trapz and just summing

30 次查看（过去 30 天）
jenka
jenka 2013-4-16
Dear everybody, I was wondering what is the difference between the function trapz and the sum as used below. It appears to be about the same. I am just trying to find the intersection between two histograms:
h = [16, 45, 23, 1]
g = [18, 38, 27, 5]
hn = h./sum(h);
gn = g./sum(g);
intersection = trapz(min([hn;gn]);
intersection = sum(min([hn;gn]));
Which one would be favorable over the other. It appears trapz should be better approximation.

请先登录，再回答此问题。

回答（1 个）

Matt J
Matt J 2013-4-16
If the function you've sampled and are integrating is piece-wise constant, then summing its samples will be ideal. If instead, it is piece-wise linear, the trapezoidal approximation will be ideal. You have to decide which situation more accurately describes your function.

类别

在 Help Center 和 File Exchange 中查找有关 Numerical Integration and Differentiation 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