Weird behaviour of QBarSeries

TommasoFurieriDO

Dear all, i'm facing a weird behaviour of QBarSeries (well, actually i cannot understand if the cause lies in QBarSet, QBarSeries or QChart ).

This is my minimal code example:

from PySide6.QtWidgets import QApplication, QMainWindow, QSlider, QVBoxLayout, QWidget
from PySide6 import QtCharts
from PySide6.QtCore import Qt
import numpy as np
import sys

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()

        self.central_widget = QWidget()
        self.setCentralWidget(self.central_widget)

        self.layout = QVBoxLayout(self.central_widget)

        self.nPolsSlider = QSlider(Qt.Horizontal)
        self.nPolsSlider.setMinimum(1)
        self.nPolsSlider.setMaximum(10)
        self.nPolsSlider.setValue(5)
        self.nPolsSlider.valueChanged.connect(self.update_chart)

        self.polsBarset = QtCharts.QBarSet('zernike_bp')
        self.pols = np.random.normal(0, 1, self.nPolsSlider.value())
        self.polsBarset.append(list(self.pols))
        self.polsSeries = QtCharts.QBarSeries()
        self.polsSeries.append(self.polsBarset)
        self.polsSeries.setBarWidth(1)
        self.polsChart = QtCharts.QChart()
        self.polsChart.addSeries(self.polsSeries)
        self.polsChart.createDefaultAxes()
        self.polsChart.legend().hide()
        self.polsChart.axisX(self.polsSeries).setRange(str(0),
                            str(self.nPolsSlider.value()))
        self.polsChartView = QtCharts.QChartView(self.polsChart)

        self.layout.addWidget(self.nPolsSlider)
        self.layout.addWidget(self.polsChartView)

        self.update_chart()

    def update_chart(self):

        self.pols = np.random.normal(0, 1, self.nPolsSlider.value())
        self.polsSeries.remove(self.polsBarset)  # remove old QBarSet
        self.polsBarset = QtCharts.QBarSet('zernike_bp')  # Create new QBarSet
        self.polsBarset.append(list(self.pols))
        self.polsSeries.append(self.polsBarset)
        self.polsChart.axisX(self.polsSeries).setRange(str(0), str(self.nPolsSlider.value()))

app = QApplication(sys.argv)
window = MainWindow()
window.show()
sys.exit(app.exec())

What happens is that the initial value of the slider (thus the initial dimension of the QBarSet) is alwais the maximum value the chart can show. It can shrink, but it cannot grow higher.

Can you guess what i'm doing wrong?

moreover i noticed a deprecation warning

DeprecationWarning: Function: 'QChart.axisX(QAbstractSeries * series) const' is marked as deprecated

What is the correct code?

Thanks you all for your precious support

TommasoFurieri

@TommasoFurieriDO i solved it calling self.polsChart.createDefaultAxes() inside the update_chart(self) function.

I actually don't know if this is actually needed or if there is a better way to do so.