Commit: 3f18b31e4b2653494ad2c1e8d4bd01f5b0d5d92a - GaloisField (hg)

A small kernel of code for playing with Galois fields of arbitrary characteristic

Commit MetaInfo

• Révision: 3f18b31e4b2653494ad2c1e8d4bd01f5b0d5d92a (tree)
• l'heure: 2016-04-17 05:22:07
• Auteur: Eric Hopper <hopper@omni...>
• Commiter: Eric Hopper

Message de Log

Initial version of Galois Field code.

Change Summary

• add: gf.py
• add: test_gf2.py

Modification

diff -r 000000000000 -r 3f18b31e4b26 gf.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gf.py	Sat Apr 16 16:22:07 2016 -0400
@@ -0,0 +1,17 @@
+def gfMeta(prime, basis):
+    prime = int(prime)
+    basis = tuple((int(p) for p in basis))
+    for p in basis:
+        if (p < 0) or (p >= prime):
+            raise ValueError("Each element of basis must be >= 0 "
+                             "and < prime.")
+    if basis[0] != 1:
+        raise ValueError("First element of basis must be 1")
+    size = len(basis)
+
+    class gf(type):
+        def __init__(self, val):
+            val = tuple((int(v) for v in val))
+            if len(val) != size:
+                raise ValueError("val must be sequence of size size of ints")
+            self.val_ = val_

diff -r 000000000000 -r 3f18b31e4b26 test_gf2.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test_gf2.py	Sat Apr 16 16:22:07 2016 -0400
@@ -0,0 +1,34 @@
+import collections
+
+def generate(p, b=2):
+    m = 1
+    while m < p:
+        m *= 2
+    m = m // 2
+    d = []
+    s = 1
+#    print(s, m)
+    generated = set()
+    while s not in generated:
+#        print(len(d), s)
+        d.append(s)
+        generated.add(s)
+        s *= b
+        while s >= m:
+            tmp = p << (s.bit_length() - p.bit_length())
+#            print(s, tmp)
+            s ^= tmp
+    return d
+
+class testit(object):
+    def __init__(self, *args, **kargs):
+        print("__init__(args = %s, kargs = %s)" % (repr(args), repr(kargs)))
+    def __getattr__(self, *args, **kargs):
+        print("__getattr__(args = %s, kargs = %s)" % (repr(args), repr(kargs)))
+        return None
+    def __prepare__(self, *args, **kargs):
+        print("__prepare__(args = %s, kargs = %s)" % (repr(args), repr(kargs)))
+        return None
+    def __call__(self, *args, **kargs):
+        print("__call__(args = %s, kargs = %s)" % (repr(args), repr(kargs)))
+        return object()