fig10_10.m

来自「数字信号处理Matlab演示文件,其中各个文件加放置了不同的matlab子文件」· M 代码 · 共 44 行

echo on
% Fig 10-10
% (a) 64 pt FFT without zero padding
% (b) 64 pt FFT with zero padding to 256 pt
% (c) 256 pt FFT without zero padding
echo off
n1=0:1:63;			% data size
N=256;				% padded FFT size

x = sin(2*pi*n1*3/64);
X = fft(x);

figure(1);
plot(n1,20*log10(abs(X)/64))
axis([0 32 -100 0])
xlabel('frequency bin')
ylabel('gain (dB)')
fprintf(1,'Press return to continue\n');
pause;

Y = fft(x,N);			% zero-padded to 256
bin=0:1:N-1;

figure(2);
plot(bin,20*log10(abs(Y)/64))
axis([0 128 -100 0])
xlabel('frequency bin')
ylabel('gain (dB)')
fprintf(1,'Press return to continue\n');
pause;

n2=0:1:255;			% data size
z= sin(2*pi*n2*3/256);
Z = fft(z);

figure(3);
plot(n2,20*log10(abs(Z)/256))
axis([0 128 -100 0])
xlabel('frequency bin')
ylabel('gain (dB)')