matlab.zip_des_matlab des加密_matlab fuliye1_newynd_pour4vv

Fs = 128; T = 1/Fs; L = 256; t = (0:L-1)*T; x = 5 + 7*cos(2*pi*15*t - 30*pi/180) + 3*cos(2*pi*40*t - 90*pi/180); y = x + randn(size(t)); figure; plot(t,y) title('noise') xlabel('time(s)') N = 2^nextpow2(L); Y = fft(y,N)/N*2; f = Fs/N*(0:1:N-1); A = abs(Y); P = angle(Y); figure; subplot(211);plot(f(1:N/2),A(1:N/2)); title('fuzhipinpu'); xlabel('pinlv(Hz)'); ylabel('fuzhi'); subplot(212); plot(f(1:N/2),P(1:N/2)); title('xiangweipinpu'); xlabel('pinlv(Hz)'); ylabel('xiangwei');