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Check spectrum analyzer for new data



flag = isNewDataReady(scope) indicates whether the spectrum analyzer scope displays new spectral estimates. When logging spectrum analyzer data from the spectrumAnalyzer scope, use this function to ignore duplicate spectra from the getSpectrumData function.


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Generate a discrete sine wave. Then display the sine wave signal using the Spectrum Analyzer. While the Spectrum Analyzer is running, save the spectrum data to a table. The Spectrum Analyzer does not update at every time step. To avoid saving that redundant spectrum data, use the isNewDataReady function.

wave = dsp.SineWave(Frequency=100,SampleRate=1000);
wave.SamplesPerFrame = 1000;
scope = spectrumAnalyzer(SampleRate=wave.SampleRate,...
data = [];

for ii = 1:250
    x = wave() + 0.05*randn(1000,1);
    if scope.isNewDataReady
        data = [data;getSpectrumData(scope)];


Show the first five rows in the table. You can see gaps in the simulation time in the data table. The missing rows indicate times where the Spectrum Analyzer was waiting for additional samples to update the spectrum. The isNewDataReady function prevented the script from saving that redundant data.


Input Arguments

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Spectrum analyzer from which you want to save data, specified as a spectrumAnalyzer object.

Output Arguments

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Flag indicating new data, returned as one of these:

  • true –– The Spectrum Analyzer shows new data.

  • false –– The Spectrum Analyzer shows the same spectrum and no new data is available.

Version History

Introduced in R2017b

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Not recommended starting in R2022a