pythonpyqtpyqtgraph

Slider widget for PyQtGraph


Is it possible to get a slider widget for PyQtGraph? So that e.g. one or more widgets could control parameters from a plot. Like in this example below (made with enaml/chaco):

enter image description here

I could find nothing like this in the examples or in the list of PyQtGraph widgets. Perhaps one can use a widget from Qt and link it to the PyQtGraph plot object?


Solution

  • It is possible to use any widget of Qt next to pyqtgraph, the graphic objects of pyqtgraph inherit from QWidget, that is to say, they are generics widgets. Here is an example.

    import sys
    
    from PyQt5.QtCore import Qt
    from PyQt5.QtWidgets import QApplication, QHBoxLayout, QLabel, QSizePolicy, QSlider, QSpacerItem, \
        QVBoxLayout, QWidget
    
    import pyqtgraph as pg
    import numpy as np
    
    
    class Slider(QWidget):
        def __init__(self, minimum, maximum, parent=None):
            super(Slider, self).__init__(parent=parent)
            self.verticalLayout = QVBoxLayout(self)
            self.label = QLabel(self)
            self.verticalLayout.addWidget(self.label)
            self.horizontalLayout = QHBoxLayout()
            spacerItem = QSpacerItem(0, 20, QSizePolicy.Expanding, QSizePolicy.Minimum)
            self.horizontalLayout.addItem(spacerItem)
            self.slider = QSlider(self)
            self.slider.setOrientation(Qt.Vertical)
            self.horizontalLayout.addWidget(self.slider)
            spacerItem1 = QSpacerItem(0, 20, QSizePolicy.Expanding, QSizePolicy.Minimum)
            self.horizontalLayout.addItem(spacerItem1)
            self.verticalLayout.addLayout(self.horizontalLayout)
            self.resize(self.sizeHint())
    
            self.minimum = minimum
            self.maximum = maximum
            self.slider.valueChanged.connect(self.setLabelValue)
            self.x = None
            self.setLabelValue(self.slider.value())
    
        def setLabelValue(self, value):
            self.x = self.minimum + (float(value) / (self.slider.maximum() - self.slider.minimum())) * (
            self.maximum - self.minimum)
            self.label.setText("{0:.4g}".format(self.x))
    
    
    class Widget(QWidget):
        def __init__(self, parent=None):
            super(Widget, self).__init__(parent=parent)
            self.horizontalLayout = QHBoxLayout(self)
            self.w1 = Slider(-10, 10)
            self.horizontalLayout.addWidget(self.w1)
    
            self.w2 = Slider(-1, 1)
            self.horizontalLayout.addWidget(self.w2)
    
            self.w3 = Slider(-10, 10)
            self.horizontalLayout.addWidget(self.w3)
    
            self.w4 = Slider(-10, 10)
            self.horizontalLayout.addWidget(self.w4)
    
            self.win = pg.GraphicsWindow(title="Basic plotting examples")
            self.horizontalLayout.addWidget(self.win)
            self.p6 = self.win.addPlot(title="My Plot")
            self.curve = self.p6.plot(pen='r')
            self.update_plot()
    
            self.w1.slider.valueChanged.connect(self.update_plot)
            self.w2.slider.valueChanged.connect(self.update_plot)
            self.w3.slider.valueChanged.connect(self.update_plot)
            self.w4.slider.valueChanged.connect(self.update_plot)
    
        def update_plot(self):
            a = self.w1.x
            b = self.w2.x
            c = self.w3.x
            d = self.w4.x
            x = np.linspace(0, 10, 100)
            data = a + np.cos(x + c * np.pi / 180) * np.exp(-b * x) * d
            self.curve.setData(data)
    
    
    if __name__ == '__main__':
        app = QApplication(sys.argv)
        w = Widget()
        w.show()
        sys.exit(app.exec_())
    

    enter image description here

    enter image description here