[PyQt] Assign Label Text as number in Hz

[mekha]

You can use a QTimer for that;

def __init__(self):
	self.timer = QtCore.QTimer(interval=1000)
	self.timer.timeout.connect(self.update)
	self.timer.start()

def update(self):
	print("Hello world")

Thank you for your reply, can you tell me more specific where I should put this code? I'm so sorry the codes I've showed is the last update of my friend before I get entrusted with this project

I'll show you the rest of the code, maybe you can take a look of it

this codes belong to the main window

from PyQt4 import QtCore, QtGui

try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _fromUtf8(s):
        return s

try:
    _encoding = QtGui.QApplication.UnicodeUTF8
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName(_fromUtf8("MainWindow"))
        MainWindow.resize(800, 620)
        self.centralwidget = QtGui.QWidget(MainWindow)
        self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
        self.frame = QtGui.QFrame(self.centralwidget)
        self.frame.setGeometry(QtCore.QRect(0, 0, 801, 611))
        self.frame.setFrameShape(QtGui.QFrame.NoFrame)
        self.frame.setFrameShadow(QtGui.QFrame.Plain)
        self.frame.setObjectName(_fromUtf8("frame"))
        self.grFFT = PlotWidget(self.frame)
        self.grFFT.setGeometry(QtCore.QRect(10, 30, 781, 241))
        self.grFFT.setObjectName(_fromUtf8("grFFT"))
        self.grPCM = PlotWidget(self.frame)
        self.grPCM.setGeometry(QtCore.QRect(10, 300, 781, 241))
        self.grPCM.setObjectName(_fromUtf8("grPCM"))
        self.pbLevel = QtGui.QProgressBar(self.frame)
        self.pbLevel.setGeometry(QtCore.QRect(10, 550, 791, 23))
        self.pbLevel.setMaximum(1000)
        self.pbLevel.setProperty("value", 123)
        self.pbLevel.setObjectName(_fromUtf8("pbLevel"))
        self.label_2 = QtGui.QLabel(self.frame)
        self.label_2.setGeometry(QtCore.QRect(10, 10, 948, 13))
        self.label_2.setObjectName(_fromUtf8("label_2"))
        self.label_3 = QtGui.QLabel(self.frame)
        self.label_3.setGeometry(QtCore.QRect(10, 280, 721, 20))
        self.label_3.setObjectName(_fromUtf8("label_3"))
        self.pushButton = QtGui.QPushButton(self.frame)
        self.pushButton.setGeometry(QtCore.QRect(10, 580, 191, 23))
        self.pushButton.setObjectName(_fromUtf8("pushButton"))
        MainWindow.setCentralWidget(self.centralwidget)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow", None))
        self.label_2.setText(_translate("MainWindow", "frequency data (FFT):", None))
        self.label_3.setText(_translate("MainWindow", "raw data (PCM):", None))
        self.pushButton.setText(_translate("MainWindow", "PushButton", None))

from pyqtgraph import PlotWidget

and this codes is to run the entire above codes (along with the one I posted before)

from PyQt4 import QtGui,QtCore

import sys
import ui_main
import numpy as np
import pyqtgraph
import SWHear

class SoundApp(QtGui.QMainWindow, ui_main.Ui_MainWindow):
    def __init__(self, parent=None):
        pyqtgraph.setConfigOption('background', 'w') #before loading widget
        super(SoundApp, self).__init__(parent)
        self.setupUi(self)
        self.grFFT.plotItem.showGrid(True, True, 0.7)
        self.grPCM.plotItem.showGrid(True, True, 0.7)
        self.maxFFT=0
        self.maxPCM=0
        self.ear = SWHear.SWHear(rate=44100,updatesPerSecond=20)
        self.ear.stream_start()

    def update(self):
        if not self.ear.data is None and not self.ear.fft is None:
            pcmMax=np.max(np.abs(self.ear.data))
            if pcmMax>self.maxPCM:
                self.maxPCM=pcmMax
                self.grPCM.plotItem.setRange(yRange=[-pcmMax,pcmMax])
            if np.max(self.ear.fft)>self.maxFFT:
                self.maxFFT=np.max(np.abs(self.ear.fft))
                #self.grFFT.plotItem.setRange(yRange=[0,self.maxFFT])
                self.grFFT.plotItem.setRange(yRange=[0,1])
            self.pbLevel.setValue(1000*pcmMax/self.maxPCM)
            pen=pyqtgraph.mkPen(color='b')
            self.grPCM.plot(self.ear.datax,self.ear.data,pen=pen,clear=True)
            pen=pyqtgraph.mkPen(color='r')
            self.grFFT.plot(self.ear.fftx,self.ear.fft/self.maxFFT,pen=pen,clear=True)
        QtCore.QTimer.singleShot(1, self.update) # QUICKLY repeat

if __name__=="__main__":
    app = QtGui.QApplication(sys.argv)
    form = SoundApp()
    form.show()
    form.update() #start with something
    app.exec_()
    print("DONE")

it'll be easier if you run it, the all .py codes I put it here in my drive
Sound App