examples: fixed examples (pfb and tags) to print an error when python modules are not available.

1 files changed, 33 insertions, 1 deletions

diff --git a/gnuradio-examples/python/pfb/resampler.py b/gnuradio-examples/python/pfb/resampler.py
index 6be7cf14e..7b296ca71 100755
--- a/gnuradio-examples/python/pfb/resampler.py
+++ b/gnuradio-examples/python/pfb/resampler.py
@@ -1,7 +1,39 @@
 #!/usr/bin/env python
+#
+# Copyright 2009 Free Software Foundation, Inc.
+# 
+# This file is part of GNU Radio
+# 
+# GNU Radio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+# 
+# GNU Radio is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with GNU Radio; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+# 
 
 from gnuradio import gr, blks2
-import scipy, pylab
+import sys
+
+try:
+    import scipy
+except ImportError:
+    print "Error: Program requires scipy (see: www.scipy.org)."
+    sys.exit(1)
+
+try:
+    import pylab
+except ImportError:
+    print "Error: Program requires matplotlib (see: matplotlib.sourceforge.net)."
+    sys.exit(1)
 
 class mytb(gr.top_block):
     def __init__(self, fs_in, fs_out, fc, N=10000):