[Question] Matplotlib plot is appending data points to plot instead of changing them

[FilipeDVelosa]

Question

I am using a matplotlib plot in my program where I display the data and after pressing a button the plot should be updated (for now I am using random data, but this should come from a device). I can get the data to be displayed in the plot but after pressing the button a second time, the data points just accumulate in the plot instead of having completely new points. Pressing further the button just adds more points. Any idea of what might be causing this? I am attaching a part of the code that is responsible for this function.

Code sample

class Visualization(UserControl):    
    def __init__(self):
        super().__init__()
        self.spectrometer = OSA()
        self.text = Text(value='0')
        self.spectraChart = LineChart()
        self.spectraAcquire = flet.ElevatedButton(text='Acquire',
                                                  on_click=self.PlotSpectralData)
        self.startMeasurement = flet.ElevatedButton(text='Start',
                                                    on_click=self.measure)
        self.abortMeasurement = flet.ElevatedButton(text='Abort',
                                                    on_click=self.abort_measurement)
        self.fig, self.ax = plt.subplots()
        self.linePlot = self.ax.scatter([], [])
        self.SpectraPlot = MatplotlibChart(self.fig)

    def PlotSpectralData(self, e):
        dataX, dataY = self.spectrometer.get_spectra()
        self.linePlot = self.ax.plot(np.array(dataX), np.array(dataY))
        self.SpectraPlot.update()

    def build(self):
        return Container(content=Column(controls=[Row([self.text]),
                                                  Row([self.SpectraPlot], height=300),
                                                  self.spectraAcquire,
                                                  self.startMeasurement,
                                                  self.abortMeasurement]))

Error message

No response

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• I have searched for answers to my question both in the issues and in previous discussions.

[fsmosca]

Could you provide a minimal reproducible code?