integration of FFT

3 次查看（过去 30 天）
Anita
Anita 2014-12-19
评论： Anita 2014-12-19
I am supposed to calculate the fft of a rect function, and then getting the integration of answer. what I have done is :
fs = ceil(4*pi)+1;
xend = 3;
t = (0:1/fs:xend-1/fs)-1/3*xend;
x_f = zeros([1,fs*xend]);
x_f(1,(1/3*xend*fs):(2/3*xend*fs-1)) = 5.7737e19.*ones([1,(1/3*xend*fs)]);
m_f = length(x_f);
n = pow2(nextpow2(m_f))*4;
y = fft(x_f,n);
f = (0:n-1)*(fs/n);
power = y.* conj(y)/n;
y0 = fftshift(y); f0 = (-n/2:n/2-1)*(fs/n)/pi;
power0 = abs(y0);
plot(f0,power0);
K_fourier=power0;
K_int = int(K_fourier, -pi, pi);
then, I have this error: Undefined function 'int' for input arguments of type 'double'.
could anyone help me please?
Thank you

请先登录，再回答此问题。

采纳的回答

Star Strider
Star Strider 2014-12-19
Use the trapz function.

更多回答（2 个）

Thorsten
Thorsten 2014-12-19
The is no such function as int in Matlab. What is int supposed to do?
Shoaibur Rahman
Shoaibur Rahman 2014-12-19
编辑：Shoaibur Rahman 2014-12-19
K_fourier is double type in your code. int cannot take double type as the function.
@ Thorsten: int performs all symbolic, definite, and indefinite integration of a function defined, and given as the input argument to int.
  1 个评论
Anita
Anita 2014-12-19
Thanks for your answer. Well, I'm aware about it and searching for a way to get the integration somehow. do you have any idea if it is possible to get integral of a 1x256 complex double or any other way to solve this problem?

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Fourier Analysis and Filtering 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