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Set nondefault values for feature extractor object



    setExtractorParameters(sFE,featurename,params) specifies the parameters used to extract featurename.

    setExtractorParameters(sFE,featurename) sets the parameters used to extract featurename to their default values.


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    Create a signalFrequencyFeatureExtractor object to extract the Welch power spectral density (PSD) estimate of a signal consisting of a 100 Hz sinusoid in additive N(0,1) white noise. The sample rate is 1 kHz and the signal has a duration of 5 seconds.

    fs = 1000;
    t = 0:1/fs:5-1/fs;
    x = cos(2*pi*100*t) + randn(size(t));
    sFE = signalFrequencyFeatureExtractor(SampleRate=fs,WelchPSD=true);

    For the PSD computation, set the OverlapLength to 25 samples and the FFTLength to 512 samples. Call the getExtractorParameters function on the object to view the PSD parameters.

    params = getExtractorParameters(sFE,"WelchPSD")
    params = struct with fields:
              FFTLength: 1024
        FrequencyVector: []
          OverlapLength: 25
                 Window: []

    Use the extract function to extract the Welch's PSD estimate of the signal. Plot the result.

    feature = extract(sFE,x);
    fvec = linspace(0,fs/2,length(feature));
    xlabel("Frequency (Hz)")
    ylabel("PSD (dB/Hz)")

    Input Arguments

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    Feature extractor object, specified as a signalFrequencyFeatureExtractor object.

    Extracted feature, specified as a string scalar or a character vector.

    Data Types: char | string

    Parameters used to extract featurename, specified as name-value arguments or a structure.

    Data Types: string | struct

    Introduced in R2021b