程序检查，错误更改（轴承内圈故障频率）

wljiron

d=6.75;
D=48.5;
a=0;
n=16;
N=0:15;
fr = N/60;
f =0.5*n*(1+d*cos(a)/D)*fr; % Frequency to find
      t = 0:0.001:10;         % Create time vector
      x = sin(2*pi*f*t);   % create a signal
    nfft = 64;           % Window should be less than 256.
    Fs = 1/dt;           % Sampling frequency
  window = hanning(nfft); % Use hanning as window
  [Pxx, F] = calc_psd(x, nfft, Fs, window);
       plot(F,Pxx); xlabel('Frequency [Hz]'); ylabel('Amplitude');

运行不出来，不知道哪里出了问题~~谢谢各位前辈的帮忙了~~