-import sys, os
-from PyQt4 import Qt, QtCore, QtGui
-import PyQt4.Qwt5 as Qwt
-from optparse import OptionParser
-from gnuradio import gr, blks2, eng_notation
-from scipy import fftpack
+try:
+ from PyQt4 import Qt, QtCore, QtGui
+except ImportError:
+ print "Please install PyQt4 to run this script (http://www.riverbankcomputing.co.uk/software/pyqt/download)"
+ raise SystemExit, 1
+
+try:
+ import PyQt4.Qwt5 as Qwt
+except ImportError:
+ print "Please install PyQwt5 to run this script (http://pyqwt.sourceforge.net/)"
+ raise SystemExit, 1
+
+try:
+ from pyqt_filter import Ui_MainWindow
+except ImportError:
+ print "Could not import from pyqt_filter. Please build with \"pyuic4 pyqt_filter.ui -o pyqt_filter.py\""
+ raise SystemExit, 1