sin22.m

可以进行傅立叶变换的matlab程序 保证可以使用

clear
x=0:0.001:50;
y=2*sin(2*pi*x)+sin(pi*x)+sin(3*pi*x)+5;
%figure
%plot(x,y,'r-');

n=16
dim=2^n;
inc=50/(2^n-1);

xf=0:inc:50;

t=interp1(x,y,xf);
offset=sum(t)/dim;
f=fft(t-offset,dim)/dim;
f2=2*abs(f(1:dim/2));

figure
plot(xf,t,'r-');
xlabel('X:time');
ylabel('Y(arb. units)');

figure
freq=0.02:1/inc/(dim-1):0.5/inc;
plot(freq,f2,'r-');
axis([0 10 0 3])
xlabel('Freq');
ylabel('Intensity (arb. units)');