Matlab 错误：产品：不一致的参数（op1 为 131072x1，op2 为 128000x1）

Question

我正在尝试在 matlab 代码中将两个向量相乘。但在这一行中，

fHatNoisy  = indices.*fHat 

它说错误，

 error: product: non-conformant arguments (op1 is 131072x1, op2 is 128000x1)

尽管我尝试添加运算符“.”我仍然收到错误..

知道为什么会出现此错误吗？

总代码：

[samples,samplingRate] = audioread('car.wav')
dt=1/samplingRate
sampleLength=length(samples)
duration = sampleLength/samplingRate
time = 0:dt:duration #time vector
n=length(time)

%disp("sampling Rate"+Fs)

fHat = fft(samples, n)
%psd = periodogram (fHat)
PSD = periodogram (fHat)
indices = PSD<0.01 #Find all freqs with large power
PSDClean1 = PSD.*indices #find out all others(While there are 0s, PSDs which are there will be 0 from indices vector)
fHatNoisy  = fHat.*indices #Zero out small Fourier coeffs. in Y

更新：这是因为两个数组，fHat和索引的长度不相等，这就是我怀疑发生错误的原因。试图找出为什么 fft() 返回的数组大小与 PSD = fHat * conj(fHat)/n （即 PSD = periodogram (fHat)）不同的数组大小

有关 PSD、N、它们的长度等的更多信息：

[解答]更新 2，计算 DFT/FFT 的 PSD：

pkg load signal;

[samples,samplingRate] = audioread('car.wav')

dt=1/samplingRate

sampleLength=length(samples)

n = length(samples);          % number of samples
frequencyRange = (0:n-1)*(samplingRate/n);     % frequency range
fHat = fft(samples)
power = abs(fHat).^2/n;    % power of the DFT

plot(frequencyRange,power)
xlabel('Frequency')
ylabel('Power')