input freqRange in bandpower doc example returning an error when it is a Mx2 matrix

Hello,

While reading the doc of the function bandpower, I tried the example Percentage of Power in Frequency Bands (Periodogram) (in MATLAB online).

The line

powBands = bandpower(Pxx,F,[50 150;200 300],"psd");

returned the following error:

Error using bandpower

Expected input number 3, FREQRANGE, to be a vector.

Error in bandpower>psdbandpower (line 152)

validateattributes(freqrange,{'numeric'},{'vector','finite','real',...

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Error in bandpower>timedomainbandpower (line 110)

pwr = psdbandpower(Pxx,F,freqrange);

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Error in bandpower (line 65)

pwr = timedomainbandpower(inputArgs{:});

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

which is quite incomprehensible, as the input description stipulate:

Frequency range for the band-power computation, specified as a two-element real-valued vector or as an M-by-2 real-valued matrix. M is the number of intervals along which to compute the band power.

Moreover, there is no mention about that in the Version History section

Did I miss something ?

Best regards,

Answer 1

[Torsten]

The specification of "freqRange" as Mx2 matrix was introduced in R2026a. Do you use this MATLAB version already ?

Alternatively, you can use

rng("default")

Fs = 1000;
t = 0:1/Fs:1-0.001;
x = cos(2*pi*100*t) + t.*chirp(t,220,t(end),270) + 0.2*randn(size(t));

[Pxx,F] = periodogram(x,hamming(length(x)),length(x),Fs);
periodogram(x,hamming(length(x)),length(x),Fs)

freqRange = [50 150;200 300];
powBands = [bandpower(Pxx,F,freqRange(1,:),"psd");bandpower(Pxx,F,freqRange(2,:),"psd")];
powTotal = bandpower(Pxx,F,[0 500],"psd");
powPercent = 100*powBands/powTotal

powPercent = 2×1

76.0390 20.6880

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