[問題] Fourier轉換

[dammmit (78$)]

題目是這樣

     ┌cosx , 0 < x < π/2
f(x) ┤                     ,f(x+π)=f(x)
     └0    , π/2 < x < π


以下是我的程式碼
--------------------------------------------------------
 1　syms x;
 2  T=pi;
 3  w0=2*pi/T;
 4  p=T/2;
 5  t=[-p:0.01:p];
 6  fx=cos(x)*(heaviside(x)-heaviside(x-pi/2));
 7  ft=cos(t)*(heaviside(t)-heaviside(t-pi/2));
 8  fn=0.;k=0;
 9  for n=-10:10
10      k=k+1;
11      wn(k)=n*w0;
12  c=double(1./T*int(fx*exp(-i*wn(k)*x),x,-p,p));
13  d(k)=abs(c);
14  fn=fn+c*exp(i.*wn(k)*t);
15  end
16  subplot(3,1,1),plot(t,real(fn),t,ft,'r')
17  subplot(3,1,2),plot(wn,d,'o')
18  subplot(3,1,3),bar(wn,d)
--------------------------------------------------------
Run出來的結果一直出現
Error using  *
Inner matrix dimensions must agree.
有沒有眼尖的大大可以幫幫忙THX^^~~

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→ ejialan:ft=cos(t).*(heaviside(t)-heaviside(t-pi/2));
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