initial commit

python/latex_gen/hamming_gen.py

@@ -0,0 +1,99 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+"""
+Generates latex tables for hamming codes
+
+(C) 2022 Louis Heredero  louis.heredero@edu.vs.ch
+"""
+
+start = r"""  \begin{tabu}{|[2pt]c|c|c|c|c|c|c|c|[2pt]}
+    \tabucline[2pt]{-}
+     & 1 & 2 & 3 & 4 & 5 & 6 & 7 \\
+    \tabucline[1pt]{-}
+"""
+
+end = r"""    \tabucline[2pt]{-}
+  \end{tabu}
+"""
+
+class HammingError(Exception):
+    pass
+
+def encode(data, blocksize=7):
+    A = start
+    B = start
+
+    result = []
+    datasize = blocksize-blocksize.bit_length()
+    data = list(map(int, data))
+    if len(data) % datasize:
+        raise HammingError(f"Length of data is not a multiple of {datasize}")
+
+    nblocks = int(len(data)/datasize)
+
+    last = 0
+    for b in range(nblocks):
+        if b > 0:
+            A += "    \\hline\n"
+            B += "    \\hline\n"
+        A += f"    Group {b+1}"
+        B += f"    Group {b+1}"
+        count = 0
+        for i in range(blocksize):
+            A += " & "
+            count += data[0]
+            # Power of 2
+            if (i+1)&i == 0 or i == 0:
+                A += "\_"
+                result.append(0)
+
+            else:
+                A += str(data[0])
+                result.append(data.pop(0))
+        A += " \\\\\n"
+
+        for i in range(blocksize.bit_length()):
+            p = 1 << i
+            c = sum([result[b*blocksize+j] for j in range(blocksize) if (j+1)&p])
+            if c%2:
+                result[b*blocksize+p-1] = 1
+
+        for i in range(blocksize):
+            B += " & "
+            B += str(result[b*blocksize+i])
+        B += " \\\\\n"
+
+        if count == 0:
+            if last >= 2:
+                A = A.rsplit("\n",2)[0]
+                A += "\n    ... & ... & ... & ... & ... & ... & ... & ... \\\\\n"
+                B = B.rsplit("\n",2)[0]
+                B += "\n    ... & ... & ... & ... & ... & ... & ... & ... \\\\\n"
+                break
+            last += 1
+        else:
+            last = 0
+
+    #return "".join(list(map(str, result)))
+    A += end
+    B += end
+
+    return A, B
+
+if __name__ == "__main__":
+    data = "00000000001111101011000010100110101100111"
+    ds = 4
+    total_bits = (3**2 * 24 - 6)
+    data_bits = total_bits * ds // 7
+    data += "0"*(ds-len(data)%ds)
+    s = ""
+    i = 0
+    left = data_bits-len(data)
+    while len(s) < left:
+        s += f"{i:0b}"
+        i += 1
+    s = s[:left]
+    data += s
+    a, b = encode(data)
+    print(a)
+    print(b)