在PlotWidget GUI中运行实时pyqtgraph

Question

I need some help with my GUI i made with PySide and Qt Designer. In my Gui code i have PlotWidget where i want to implement the pyqtgraph.

The code for PyQtGraph i am trying to implement (some example i found in internet:) graph.py :

import pyqtgraph as pg
import numpy as np
plt = pg.plot()
bufferSize = 1000
data = np.zeros(bufferSize)
curve = plt.plot()
line = plt.addLine(x=0)
plt.setRange(xRange=[0, bufferSize], yRange=[-50, 50])
i = 0
def update():
    global data, curve, line, i
    n = 10  # update 10 samples per iteration
    rand = np.random.normal(size=n)
    data[i:i+n] = np.clip(data[i-1] + rand, -50, 50)
    curve.setData(data)
    i = (i+n) % bufferSize
    line.setValue(i)

timer = pg.QtCore.QTimer()
timer.timeout.connect(update)
timer.start(20)
pg.QtGui.QApplication.instance().exec_()

This is running without command line> python> import graph.py due to pg.QtGui.QApplication.instance().exec_() line

Now i want to run this random plot in Plot Widget in my GUI.

Code From QtDesigner:

from PySide import QtCore, QtGui

class Ui_MainDialog(object):
    def setupUi(self, MainDialog):
        MainDialog.setObjectName("MainDialog")
        MainDialog.resize(400, 300)
        self.nameEdit = QtGui.QLineEdit(MainDialog)
        self.nameEdit.setGeometry(QtCore.QRect(30, 50, 181, 31))
        self.nameEdit.setText("")
        self.nameEdit.setObjectName("nameEdit")
        self.showButton = QtGui.QPushButton(MainDialog)
        self.showButton.setGeometry(QtCore.QRect(250, 50, 101, 31))
        self.showButton.setObjectName("showButton")
        self.MainGraph = PlotWidget(MainDialog)
        self.MainGraph.setGeometry(QtCore.QRect(70, 100, 256, 192))
        self.MainGraph.setObjectName("MainGraph")

        self.retranslateUi(MainDialog)
        QtCore.QMetaObject.connectSlotsByName(MainDialog)
        MainDialog.setTabOrder(self.showButton, self.nameEdit)
        MainDialog.setTabOrder(self.nameEdit, self.MainGraph)

    def retranslateUi(self, MainDialog):
        MainDialog.setWindowTitle(QtGui.QApplication.translate("MainDialog", "MainDialog", None, QtGui.QApplication.UnicodeUTF8))
        self.nameEdit.setPlaceholderText(QtGui.QApplication.translate("MainDialog", "Log Window", None, QtGui.QApplication.UnicodeUTF8))
        self.showButton.setText(QtGui.QApplication.translate("MainDialog", "Show Graph!", None, QtGui.QApplication.UnicodeUTF8))

from pyqtgraph import PlotWidget

And now My main programm:

from PySide.QtCore import *
from PySide.QtGui import *
import example3
import sys

class Maindialog(QDialog,example3.Ui_MainDialog):

    def __init__(self, parent=None):
        super(Maindialog,self).__init__(parent)
        self.setupUi(self)
        self.connect(self.showButton,SIGNAL("clicked()"),self.showBOX)

    def showBOX(self):
        QMessageBox.information(self, "hello", "hello there  " + self.nameEdit.text())
        print"hello world"
        plt=self.MainGraph
        #z.plot(x = [0, 1, 2, 4,7,8,9,0], y = [4, 5, 9, 6,1,2,3,4])
        import numpy as np
        import pyqtgraph as pg

        bufferSize = 1000
        data = np.zeros(bufferSize)
        curve = plt.plot()
        curve.setData()
        line = plt.addLine(x=0)
        plt.setRange(xRange=[0, bufferSize], yRange=[-50, 50])
        i = 0

        def update():
              global data, curve, line, i
              n = 10  # update 10 samples per iteration
              rand = np.random.normal(size=n)
              data[i:i+n] = np.clip(data[i-1] + rand, -50, 50)
              curve.setData(data)
              i = (i+n) % bufferSize
              line.setValue(i)
        timer = pg.QtCore.QTimer()
        timer.timeout.connect(update)
        timer.start(20)
        if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
            pg.QtGui.QApplication.instance().exec_()

I have error QCoreApplication::exec: The event loop is already running

Partly i understand the problem, Pyqtgraph is made with PyQt itself and when i ask it to run the event (update the realtime graph) it says the event already working from the main gui...

Please suggest how can i implement running pyqtgraph to my gui:

appreciate for modified code:

Thanks you very much!

Answer 1

These changes to your function are required: all about keeping hold of those variables. On my system I had specific errors saying that variables were undefined to aid with this.

def showBOX(self):
    QMessageBox.information(self, "hello", "hello there  " + self.nameEdit.text())
    print"hello world"
    plt=self.MainGraph
    #z.plot(x = [0, 1, 2, 4,7,8,9,0], y = [4, 5, 9, 6,1,2,3,4])
    import numpy as np
    import pyqtgraph as pg

    bufferSize = 1000
    self.data = np.zeros(bufferSize)
    self.curve = plt.plot()
    self.curve.setData()
    self.line = plt.addLine(x=0)
    plt.setRange(xRange=[0, bufferSize], yRange=[-50, 50])
    self.i = 0

    def update():
          n = 10  # update 10 samples per iteration
          rand = np.random.normal(size=n)
          self.data[self.i:self.i+n] = np.clip(self.data[self.i-1] + rand, -50, 50)
          self.curve.setData(self.data)
          self.i = (self.i+n) % bufferSize
          self.line.setValue(self.i)
    self.update = update
    self.timer = pg.QtCore.QTimer()
    self.timer.timeout.connect(self.update)
    self.timer.start(20)