def plotEMGGraphs(self):
    x = self.emg_xValues
    self.plotsEMG[:] = []

    self.EMGlayout = QGridLayout()

    for i in range(self.emg_yValues.__len__()):
        plotWidget = pg.PlotWidget()
        self.plotsEMG.append(plotWidget)
        hideShowButton = QPushButton()
        self.hideAndShowButtonPlotsEMG.append(hideShowButton)
        self.hidAndShowButtonIsShowed.append(True)
        QtCore.QObject.connect(self.hideAndShowButtonPlotsEMG[i], QtCore.SIGNAL("clicked()"), functools.partial(self.showHideGraph, i))

    for i in range(self.emg_yValues.__len__()):
        # -------------- adding graphs --------------#
        y = self.emg_yValues[i]
        self.plotsEMG[i].setBackground(None)

        self.plotsEMG[i].setLabel('left', "Tension", units='V')
        self.plotsEMG[i].setLabel('bottom', "Time", units='s')
        self.plotsEMG[i].setTitle("EMG : " + str(self.emg_column_names[i+1]))
        self.plotsEMG[i].setMouseEnabled(False)

        thePenForEMG = pg.mkPen(color=(72,118,255), width=2)
        plot = self.plotsEMG[i].plot(x, y, pen=thePenForEMG)

        thePenForHandVLines = pg.mkPen(color=(166,166,166), width=2)
        hLine = pg.InfiniteLine(angle=0, movable=False, pen=thePenForHandVLines)
        self.vLines.append(pg.InfiniteLine(angle=90, movable=False, pen=thePenForHandVLines))
        self.vLines[i].setPos(self.plotEMGXRangeVLineValue)
        hLine.setPos(0)
        self.plotsEMG[i].addItem(self.vLines[i], ignoreBounds=True)
        self.plotsEMG[i].addItem(hLine, ignoreBounds=True)
        self.plotsEMG[i].setXRange(self.plotEMGXRangeMin, self.plotEMGXRangeMax, update=True)
        self.plotsEMG[i].setYRange(0-self.plotEMGYRangeMaxABS, self.plotEMGYRangeMaxABS)
        self.EMGlayout.addWidget(self.plotsEMG[i], i, 0)

        # ---------- adding hide/show button ----------#
        self.hideAndShowButtonPlotsEMG[i].setSizePolicy(QSizePolicy(QSizePolicy.Fixed, QSizePolicy.Fixed))
        self.hideAndShowButtonPlotsEMG[i].setText("Hide EMG " + str(i+1))
        self.EMGlayout.addWidget(self.hideAndShowButtonPlotsEMG[i], i, 1)
        #self.verticalLayout_17.addWidget(self.plotsEMG[i])


    previewButton = QPushButton(self.tab_4)
    previewButton.setText("Preview")
    QtCore.QObject.connect(previewButton, QtCore.SIGNAL("clicked()"), self.previewViewEMG)
    self.EMGlayout.addWidget(previewButton)

    nextButton = QPushButton(self.tab_4)
    nextButton.setText("Next")
    QtCore.QObject.connect(nextButton, QtCore.SIGNAL("clicked()"), self.nextViewEMG)
    self.EMGlayout.addWidget(nextButton)


    wid = QWidget()
    wid.setLayout(self.EMGlayout)
    scroll = QScrollArea()
    scroll.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
    scroll.setVerticalScrollBarPolicy(Qt.ScrollBarAsNeeded)
    scroll.setWidgetResizable(False)
    scroll.setWidget(wid)
    sizePolicy = QSizePolicy(QSizePolicy.Expanding, QSizePolicy.Expanding)
    scroll.setSizePolicy(sizePolicy)
    self.verticalLayout_17.addWidget(scroll)