PeakFinderConfiguration

Compute and display the largest calculated peak values on the scope display

Since R2023a

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    Description

    Use the PeakFinderConfiguration object to compute and display peaks in the scope. The scope computes and displays peaks for only the portion of the input signal that is currently on display in the scope.

    You can specify the number of peaks you want the scope to display, the minimum height above which you want the scope to detect peaks, the minimum distance between peaks, and label the peaks. You can control the peak finder settings from the scope toolstrip or from the command line. The algorithm defines a peak as a local maximum with lower values present on either side of the peak. It does not consider end points as peaks. For more information on the algorithm, see the findpeaks (Signal Processing Toolbox) function.

    To modify the peak finder settings in the scope interface, click the Measurements tab and enable Peak Finder in the Peaks section. Once you enable the Peak Finder, an arrow appears on the plot at each maxima and a Peaks panel appears at the bottom of the scope window.

    The SpectrumAnalyzerBlockConfiguration object supports the PeakFinderConfiguration object in the command line.

    Spectrum Analyzer Toolstrip

    Snapshot showing peak finder measurements in Spectrum Analyzer toolstrip.

    Creation

    Syntax

    pkfinder = PeakFinderConfiguration()

    Description

    pkfinder = PeakFinderConfiguration() creates a peak finder configuration object.

    example

    Properties

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    All properties are tunable.

    Level above which the scope detects peaks, specified as a real scalar.

    Scope Window Use

    On the Measurements tab, select Peak Finder. In the peak finder settings, specify a real scalar in the Min Height box.

    Data Types: double

    Maximum number of peaks to show, specified as a positive integer less than 100.

    Scope Window Use

    On the Measurements tab, select Peak Finder. In the peak finder settings, specify a positive integer less than 100 in the Num Peaks box.

    Data Types: double

    Minimum number of samples between adjacent peaks, specified as a positive integer.

    Scope Window Use

    On the Measurements tab, select Peak Finder. In the peak finder settings, specify a positive integer in the Min Distance box.

    Data Types: double

    Minimum difference in the height of the peak and its neighboring samples, specified as a nonnegative scalar.

    Scope Window Use

    On the Measurements tab, select Peak Finder. In the peak finder settings, specify a nonnegative scalar in the Threshold box.

    Data Types: double

    Label found peaks, specified as true or false. The scope displays the labels (P1, P2, …) above the arrows in the plot.

    Scope Window Use

    On the Measurements tab, select Peak Finder. In the peak finder settings, select Label Peaks.

    Data Types: logical

    Coordinates to display next to the calculated peak value, specified as "x", "y", or "x + y".

    Data Types: char | string

    Enable peak finder measurements, specified as true or false. Set this property to true to enable the peak finder measurements.

    Scope Window Use

    On the Measurements tab, select Peak Finder.

    Data Types: logical

    Examples

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    Open Model

    Open and run the water hammer model.

    open_system('WaterHammerEffect')
sim('WaterHammerEffect')

    The Spectrum Analyzer in this model shows the power spectrum of the water pressure in the pipe. For more details on this model, see the Water Hammer Effect example.

    You can obtain or modify the peak, cursor, and distortion measurements in the spectrum programmatically by enabling these properties in the SpectrumAnalyzerConfiguration object.

    • PeakFinder

    • CursorMeasurements

    • DistortionMeasurements

    Access the configuration properties of the Spectrum Analyzer block using the get_param function.

    sablock = 'WaterHammerEffect/Spectrum Analyzer';
cfg = get_param(sablock,'ScopeConfiguration');

    To enable these measurements, set the Enabled property to true.

    cfg.CursorMeasurements.Enabled = true;
cfg.PeakFinder.Enabled = true;
cfg.DistortionMeasurements.Enabled = true;

    You can now modify these measurements programmatically. As an example, display the first five peaks in the spectrum display. By default, the spectrum shows only three peaks. To modify the number of peaks it shows, change NumPeaks to 5. You can even label the peaks using the LabelPeaks property and control the minimum distance between adjacent peaks using the MinDistance property. The changes you make to these properties update the spectra accordingly.

    cfg.PeakFinder.NumPeaks = 5;

    Version History

    Introduced in R2023a

    See Also

    Blocks

    Objects