1 files changed, 84 insertions, 0 deletions
diff --git a/gr-fec/python/fec/polar/helper_functions.py b/gr-fec/python/fec/polar/helper_functions.py
new file mode 100644
index 0000000000..1d82457f17
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+++ b/gr-fec/python/fec/polar/helper_functions.py
@@ -0,0 +1,84 @@
+#!/usr/bin/env python
+#
+# Copyright 2015 Free Software Foundation, Inc.
+#
+# 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.
+#
+
+import numpy as np
+
+
+def is_power_of_two(num):
+    if type(num) != int:
+        return False  # make sure we only compute integers.
+    return num != 0 and ((num & (num - 1)) == 0)
+
+
+def bit_reverse(value, n):
+    # is this really missing in NumPy???
+    seq = np.int(value)
+    rev = np.int(0)
+    rmask = np.int(1)
+    lmask = np.int(2 ** (n - 1))
+    for i in range(n // 2):
+        shiftval = n - 1 - (i * 2)
+        rshift = np.left_shift(np.bitwise_and(seq, rmask), shiftval)
+        lshift = np.right_shift(np.bitwise_and(seq, lmask), shiftval)
+        rev = np.bitwise_or(rev, rshift)
+        rev = np.bitwise_or(rev, lshift)
+        rmask = np.left_shift(rmask, 1)
+        lmask = np.right_shift(lmask, 1)
+    if not n % 2 == 0:
+        rev = np.bitwise_or(rev, np.bitwise_and(seq, rmask))
+    return rev
+
+
+def bit_reverse_vector(vec, n):
+    return np.array([bit_reverse(e, n) for e in vec], dtype=vec.dtype)
+
+
+def unpack_byte(byte, nactive):
+    if np.amin(byte) < 0 or np.amax(byte) > 255:
+        return None
+    if not byte.dtype == np.uint8:
+        byte = byte.astype(np.uint8)
+    if nactive == 0:
+        return np.array([], dtype=np.uint8)
+    return np.unpackbits(byte)[-nactive:]
+
+
+def pack_byte(bits):
+    if len(bits) == 0:
+        return 0
+    if np.amin(bits) < 0 or np.amax(bits) > 1:  # only '1' and '0' in bits array allowed!
+        return None
+    bits = np.concatenate((np.zeros(8 - len(bits), dtype=np.uint8), bits))
+    res = np.packbits(bits)[0]
+    return res
+
+
+def main():
+    print 'helper functions'
+
+    for i in range(8):
+        print(i, 'is power of 2: ', is_power_of_two(i))
+    n = 2 ** 6
+    k = n // 2
+    eta = 0.3
+
+
+if __name__ == '__main__':
+    main()