且构网

分享程序员开发的那些事...
且构网 - 分享程序员编程开发的那些事

在MATLAB中计算FFT图下的面积

更新时间:2023-02-27 09:10:23

使用 Matlab 进行数值集成的方法有很多.下面是一个例子:

There are many ways to do numerical integration with Matlab. Here is an example:

%# create some data
x = linspace(0,pi/2,100); %# 100 equally spaced points between 0 and pi/2
y = sin(x);

%# integrate using trapz, which calculates the area in the trapezoid defined by 
%# x(k),x(k+1),y(k),y(k+1) for k=1:length(x)
integral = trapz(x,y);

%# if you only want to integrate part of the data, do
partialIntegral = trapz(x(10:20),y(10:20));

%# show the integrated area
figure, 
area(x,y); 
hold on, 
area(x(10:20),y(10:20),'FaceColor','red')