diff --git a/ui/Ui_mainwindow.py b/ui/Ui_mainwindow.py
index 679dd05..0bec613 100644
--- a/ui/Ui_mainwindow.py
+++ b/ui/Ui_mainwindow.py
@@ -2,8 +2,7 @@
 
 # Form implementation generated from reading ui file 'mainwindow.ui'
 #
-# Created: Sat Jan 31 19:20:48 2015
-#      by: PyQt5 UI code generator 5.4
+# Created by: PyQt5 UI code generator 5.4.2
 #
 # WARNING! All changes made in this file will be lost!
 
@@ -21,8 +20,9 @@ class Ui_MainWindow(object):
         self.horizontalLayout.setObjectName("horizontalLayout")
         self.splitter = QtWidgets.QSplitter(self.centralWidget)
         self.splitter.setOrientation(QtCore.Qt.Horizontal)
+        self.splitter.setOpaqueResize(False)
         self.splitter.setHandleWidth(2)
-        self.splitter.setChildrenCollapsible(True)
+        self.splitter.setChildrenCollapsible(False)
         self.splitter.setObjectName("splitter")
         self.groupBox_experiment = QtWidgets.QGroupBox(self.splitter)
         sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Preferred)
@@ -195,26 +195,14 @@ class Ui_MainWindow(object):
         self.buttonBox_process.setObjectName("buttonBox_process")
         self.formLayout_3.setWidget(3, QtWidgets.QFormLayout.FieldRole, self.buttonBox_process)
         self.tabWidget = QtWidgets.QTabWidget(self.splitter)
+        self.tabWidget.setEnabled(True)
         sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Preferred)
-        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setHorizontalStretch(6)
         sizePolicy.setVerticalStretch(0)
         sizePolicy.setHeightForWidth(self.tabWidget.sizePolicy().hasHeightForWidth())
         self.tabWidget.setSizePolicy(sizePolicy)
         self.tabWidget.setMinimumSize(QtCore.QSize(300, 300))
         self.tabWidget.setObjectName("tabWidget")
-        #self.tab_raw = MplWidget()
-        #self.tab_raw.setObjectName("tab_raw")
-        #self.tabWidget.addTab(self.tab_raw, "")
-        #self.tab_derivative = MplWidget()
-        #self.tab_derivative.setObjectName("tab_derivative")
-        #self.tabWidget.addTab(self.tab_derivative, "")
-        #self.tab_heatmap = MplWidget()
-        #self.tab_heatmap.setObjectName("tab_heatmap")
-        #self.tabWidget.addTab(self.tab_heatmap, "")
-        #self.tab_heatmap_avg = MplWidget()
-        #self.tab_heatmap_avg.setEnabled(False)
-        #self.tab_heatmap_avg.setObjectName("tab_heatmap_avg")
-        #self.tabWidget.addTab(self.tab_heatmap_avg, "")
         self.horizontalLayout.addWidget(self.splitter)
         MainWindow.setCentralWidget(self.centralWidget)
         self.menuBar = QtWidgets.QMenuBar(MainWindow)
@@ -255,7 +243,7 @@ class Ui_MainWindow(object):
         self.label_cbar_end.setBuddy(self.doubleSpinBox_cbar_end)
 
         self.retranslateUi(MainWindow)
-        self.tabWidget.setCurrentIndex(0)
+        self.tabWidget.setCurrentIndex(-1)
         QtCore.QMetaObject.connectSlotsByName(MainWindow)
 
     def retranslateUi(self, MainWindow):
@@ -291,14 +279,9 @@ class Ui_MainWindow(object):
         self.doubleSpinBox_cbar_start.setSuffix(_translate("MainWindow", " °C"))
         self.label_cbar_end.setText(_translate("MainWindow", "En&d"))
         self.doubleSpinBox_cbar_end.setSuffix(_translate("MainWindow", " °C"))
-        #self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab_raw), _translate("MainWindow", "Raw Data"))
-        #self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab_derivative), _translate("MainWindow", "&2nd derivative"))
-        #self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab_heatmap), _translate("MainWindow", "Heatmap"))
-        #self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab_heatmap_avg), _translate("MainWindow", "Heatmap average"))
         self.menuFile.setTitle(_translate("MainWindow", "Fi&le"))
         self.menuHelp.setTitle(_translate("MainWindow", "Hel&p"))
         self.actionQuit.setText(_translate("MainWindow", "&Quit"))
         self.actionAbout.setText(_translate("MainWindow", "&About"))
         self.actionAbout_Qt.setText(_translate("MainWindow", "About &Qt"))
 
-from .mplwidget import MplWidget
diff --git a/ui/mainwindow.py b/ui/mainwindow.py
index 2f0a167..1975a5e 100644
--- a/ui/mainwindow.py
+++ b/ui/mainwindow.py
@@ -1,19 +1,11 @@
 # -*- coding: utf-8 -*-
-
 """
 Module implementing MainWindow.
 """
-from PyQt5.QtCore import (pyqtSlot,
-                          QObject,
-                          pyqtSignal,
-                          QThreadPool,
-                          QRunnable,)
-from PyQt5.QtWidgets import (QMainWindow,
-                             QProgressBar,
-                             QDialogButtonBox,
-                             QFileDialog,
-                             QMessageBox,
-                             QApplication)
+from PyQt5.QtCore import (pyqtSlot, QObject, pyqtSignal, QThreadPool,
+                          QRunnable, )
+from PyQt5.QtWidgets import (QMainWindow, QProgressBar, QDialogButtonBox,
+                             QFileDialog, QMessageBox, QApplication)
 
 from .Ui_mainwindow import Ui_MainWindow
 from .mplwidget import MplWidget
@@ -46,21 +38,29 @@ class Worker(QRunnable):
             c_lower = self.owner.doubleSpinBox_lower.value()
             c_upper = self.owner.doubleSpinBox_upper.value()
         if self.owner.groupBox_cbar.isChecked():
-            cbar_range = (self.owner.doubleSpinBox_cbar_start, self.owner.doubleSpinBox_cbar_end)
+            cbar_range = (self.owner.doubleSpinBox_cbar_start,
+                          self.owner.doubleSpinBox_cbar_end)
         if self.owner.groupBox_signal_threshold.isChecked():
             signal_threshold = self.owner.spinBox_signal_threshold.value()
 
-        items = (self.owner.listWidget_data.item(i) for i in range(self.owner.listWidget_data.count()))
+        items = (self.owner.listWidget_data.item(i)
+                 for i in range(self.owner.listWidget_data.count()))
 
         files = []
         for item in items:
             files.append(item.text())
-        self.exp = Experiment(exp_type=instrument_type, files=files, t1=self.owner.doubleSpinBox_tmin.value(), t2=self.owner.doubleSpinBox_tmax.value(),
-                              dt=self.owner.doubleSpinBox_dt.value(), cols=12, rows=8, cutoff_low=c_lower, cutoff_high=c_upper,
-                              signal_threshold=signal_threshold, color_range=cbar_range)
-        print("Start processing of data... ")
+        self.exp = Experiment(exp_type=instrument_type,
+                              files=files,
+                              t1=self.owner.doubleSpinBox_tmin.value(),
+                              t2=self.owner.doubleSpinBox_tmax.value(),
+                              dt=self.owner.doubleSpinBox_dt.value(),
+                              cols=12,
+                              rows=8,
+                              cutoff_low=c_lower,
+                              cutoff_high=c_upper,
+                              signal_threshold=signal_threshold,
+                              color_range=cbar_range)
         self.exp.analyze()
-        print("done!")
         self.signals.finished.emit()
 
 
@@ -93,7 +93,6 @@ class Tasks(QObject):
         for task in self.tasks:
             self.data.append(task.exp)
 
-        print(self.data)
         self.signals.finished.emit(self.data)
 
 
@@ -117,7 +116,11 @@ class MainWindow(QMainWindow, Ui_MainWindow):
         self.statusBar.addPermanentWidget(self.progressBar)
         self.statusBar.showMessage("Welcome to PyDSF")
 
-        self.buttonBox_process.addButton("&Start Processing", QDialogButtonBox.AcceptRole)
+        self.buttonBox_process.addButton("&Start Processing",
+                                         QDialogButtonBox.AcceptRole)
+
+        self.tasks = Tasks()
+        self.worker = Worker(self)
 
     @pyqtSlot("QAbstractButton*")
     def on_buttonBox_open_reset_clicked(self, button):
@@ -125,16 +128,15 @@ class MainWindow(QMainWindow, Ui_MainWindow):
         Slot documentation goes here.
         """
         if button == self.buttonBox_open_reset.button(QDialogButtonBox.Open):
-            filenames, filter = QFileDialog.getOpenFileNames(self, 'Open data file', '', "Text files (*.txt *.csv)")
-            self.listWidget_data.addItems(filenames)
+            filenames = QFileDialog.getOpenFileNames(
+                self, 'Open data file', '', "Text files (*.txt *.csv)")
+            self.listWidget_data.addItems(filenames[0])
             if self.listWidget_data.count() > 1:
                 self.groupBox_replicates.setChecked(True)
                 self.radioButton_rep_files.setEnabled(True)
-        elif button == self.buttonBox_open_reset.button(QDialogButtonBox.Reset):
+        elif button == self.buttonBox_open_reset.button(
+                QDialogButtonBox.Reset):
             self.listWidget_data.clear()
-            print("Data cleared")
-        # self.radioButton_rep_rows.setEnabled(False)
-        #            self.radioButton_rep_columns.setEnabled(False)
 
     @pyqtSlot("QString")
     def on_comboBox_instrument_currentIndexChanged(self, p0):
@@ -142,17 +144,12 @@ class MainWindow(QMainWindow, Ui_MainWindow):
         Slot documentation goes here.
         """
         if p0 == 'Analytik Jena qTOWER 2.0/2.2':
-            print(p0)
             self.groupBox_temp.setEnabled(True)
         else:
             self.groupBox_temp.setEnabled(False)
-        # self.groupBox_data.setEnabled(True)
-        #        self.groupBox_cutoff.setEnabled(True)
-        #        self.groupBox_cbar.setEnabled(True)
-        #        self.groupBox_signal_threshold.setEnabled(True)
 
     def generate_plot_tab(self, name):
-        tab = MplWidget()
+        tab = MplWidget(parent=self)
         tab.setObjectName(name)
         return tab
 
@@ -183,18 +180,19 @@ class MainWindow(QMainWindow, Ui_MainWindow):
         """
 
         if self.listWidget_data.count() < 1:
-            QMessageBox.critical(self, 'Error', "No data file loaded!", QMessageBox.Close, QMessageBox.Close)
+            QMessageBox.critical(self, 'Error', "No data file loaded!",
+                                 QMessageBox.Close, QMessageBox.Close)
             return
-        if self.spinBox_signal_threshold.value() == 0 and self.groupBox_signal_threshold.isChecked():
-            QMessageBox.warning(self, 'Warning', "Signal threshold is currently set to zero.", QMessageBox.Ok,
-                                QMessageBox.Ok)
+        if self.spinBox_signal_threshold.value(
+        ) == 0 and self.groupBox_signal_threshold.isChecked():
+            QMessageBox.warning(self, 'Warning',
+                                "Signal threshold is currently set to zero.",
+                                QMessageBox.Ok, QMessageBox.Ok)
 
         self.progressBar.setEnabled(True)
         self.statusBar.showMessage("Processing...")
 
-        self.tasks = Tasks()
         self.tasks.signals.finished.connect(self.on_processing_finished)
-        self.worker = Worker(self)
         self.tasks.add_task(self.worker)
         self.tasks.start()
 
@@ -203,20 +201,29 @@ class MainWindow(QMainWindow, Ui_MainWindow):
         # For now, only read the first entry
         exp = self.tasks.data[0]
 
-        save_data = QMessageBox.question(self, 'Save data', "Calculations are finished. Save results?",
-                                         QMessageBox.Yes | QMessageBox.No, QMessageBox.Yes)
+        save_data = QMessageBox.question(
+            self, 'Save data', "Calculations are finished. Save results?",
+            QMessageBox.Yes | QMessageBox.No, QMessageBox.Yes)
         if save_data == QMessageBox.Yes:
             dialog = QFileDialog()
             dialog.setFileMode(QFileDialog.Directory)
-            folder = dialog.getExistingDirectory(self, 'Choose path for results')
+            folder = dialog.getExistingDirectory(self,
+                                                 'Choose path for results')
             for plate in exp.plates:
-                plate.write_tm_table('{}/plate_{}_04_tm.csv'.format(folder, str(plate.id)))
-                plate.write_derivative_table('{}/plate_{}_03_dI_dT.csv'.format(folder, str(plate.id)))
-                plate.write_filtered_table('{}/plate_{}_02_filtered_data.csv'.format(folder, str(plate.id)))
-                plate.write_raw_table('{}/plate_{}_01_raw_data.csv'.format(folder, str(plate.id)))
+                plate.write_tm_table(
+                    '{}/plate_{}_04_tm.csv'.format(folder, str(plate.id)))
+                plate.write_derivative_table(
+                    '{}/plate_{}_03_dI_dT.csv'.format(folder, str(plate.id)))
+                plate.write_filtered_table(
+                    '{}/plate_{}_02_filtered_data.csv'.format(folder,
+                                                              str(plate.id)))
+                plate.write_raw_table('{}/plate_{}_01_raw_data.csv'.format(
+                    folder, str(plate.id)))
 
             if exp.avg_plate:
-                exp.avg_plate.write_avg_tm_table('{}/plate_{}_05_tm_avg.csv'.format(folder, str(self.worker.exp.avg_plate.id)))
+                exp.avg_plate.write_avg_tm_table(
+                    '{}/plate_{}_05_tm_avg.csv'.format(
+                        folder, str(self.worker.exp.avg_plate.id)))
 
         for i in range(len(self.worker.exp.plates)):
 
@@ -247,7 +254,7 @@ class MainWindow(QMainWindow, Ui_MainWindow):
         QApplication.quit()
 
     @pyqtSlot("bool")
-    def on_groupBox_cutoff_toggled(self, p0):
+    def on_groupBox_cutoff_toggled(self):
         """
         Slot documentation goes here.
         """
diff --git a/ui/mainwindow.ui b/ui/mainwindow.ui
index 834b463..adce451 100644
--- a/ui/mainwindow.ui
+++ b/ui/mainwindow.ui
@@ -26,11 +26,14 @@
       <property name="orientation">
        <enum>Qt::Horizontal</enum>
       </property>
+      <property name="opaqueResize">
+       <bool>false</bool>
+      </property>
       <property name="handleWidth">
        <number>2</number>
       </property>
       <property name="childrenCollapsible">
-       <bool>true</bool>
+       <bool>false</bool>
       </property>
       <widget class="QGroupBox" name="groupBox_experiment">
        <property name="sizePolicy">
@@ -463,9 +466,12 @@
        </layout>
       </widget>
       <widget class="QTabWidget" name="tabWidget">
+       <property name="enabled">
+        <bool>true</bool>
+       </property>
        <property name="sizePolicy">
         <sizepolicy hsizetype="Preferred" vsizetype="Preferred">
-         <horstretch>0</horstretch>
+         <horstretch>6</horstretch>
          <verstretch>0</verstretch>
         </sizepolicy>
        </property>
@@ -476,31 +482,8 @@
         </size>
        </property>
        <property name="currentIndex">
-        <number>0</number>
+        <number>-1</number>
        </property>
-       <widget class="MplWidget" name="tab_raw">
-        <attribute name="title">
-         <string>Raw Data</string>
-        </attribute>
-       </widget>
-       <widget class="MplWidget" name="tab_derivative">
-        <attribute name="title">
-         <string>&amp;2nd derivative</string>
-        </attribute>
-       </widget>
-       <widget class="MplWidget" name="tab_heatmap">
-        <attribute name="title">
-         <string>Heatmap</string>
-        </attribute>
-       </widget>
-       <widget class="MplWidget" name="tab_heatmap_avg">
-        <property name="enabled">
-         <bool>false</bool>
-        </property>
-        <attribute name="title">
-         <string>Heatmap average</string>
-        </attribute>
-       </widget>
       </widget>
      </widget>
     </item>
@@ -561,16 +544,6 @@
    </property>
   </action>
  </widget>
- <customwidgets>
-  <customwidget>
-   <class>MplWidget</class>
-   <extends>QWidget</extends>
-   <header>mplwidget</header>
-   <container>1</container>
-  </customwidget>
- </customwidgets>
- <resources>
-  <include location="icons.qrc"/>
- </resources>
+ <resources/>
  <connections/>
 </ui>