Revert "gcd, lcm from standard library"

This reverts commit 07e4648.

src/spectrum/calculations/graphs.py

@@ -15,7 +15,6 @@
 
 """
 import itertools
-import math
 
 from spectrum.calculations import numeric
 from spectrum.calculations.numeric import Integer
@@ -69,7 +68,7 @@ def _add_element(self, a):
         l = len(self._vertices)
         for i in range(l):
             b = self._vertices[i]
-            d = math.gcd(a, b)
+            d = numeric.gcd(a, b)
             if d == 1:
                 continue
             bd = numeric.prime_part(b, d)

src/spectrum/calculations/groups.py

@@ -14,13 +14,13 @@
    limitations under the License.
 
 """
-import math
 from functools import reduce
 
+from .partition import Partitions
 from spectrum.calculations import orders, spectra, numeric
 from spectrum.calculations.numeric import Constraints, Integer
 from spectrum.tools.tools import doc_inherit, ObjectCache
-from .partition import Partitions
+
 
 __author__ = 'Daniel Lytkin'
 
@@ -155,7 +155,7 @@ def apex(self):
             n = self._degree
             partitions = [x for x in Partitions(n) if (len(x) + n) % 2 == 0]
             self._apex = numeric.sort_and_filter(
-                [reduce(math.lcm, partition) for partition in partitions])
+                [reduce(numeric.lcm, partition) for partition in partitions])
         return self._apex
 
     @doc_inherit

src/spectrum/calculations/numeric.py

@@ -20,10 +20,36 @@
 
 __author__ = 'Daniel Lytkin'
 
-# Module providing methods to calculate some number theoretic values.
+# Module providing methods to calculate GCD and LCM etc.
 from functools import reduce
 
 
+def gcd(a, b):
+    """Calculates greatest common divisor of two numbers.
+
+    Args:
+        a, b: Integers
+
+    Returns:
+        GCD(a, b)
+    """
+    while b:
+        a, b = b, a % b
+    return a
+
+
+def lcm(a, b):
+    """Calculates least common multiple of two numbers.
+
+    Args:
+        a, b: Integers
+
+    Returns:
+        LCM(a, b)
+    """
+    return a / gcd(a, b) * b
+
+
 def prime_part(n, b):
     """Calculates b'-part of number n, which is the greatest divisor of n
     coprime to d.
@@ -36,7 +62,7 @@ def prime_part(n, b):
         Greatest divisor of n which is relatively prime to d.
     """
     while True:
-        d = math.gcd(n, b)
+        d = gcd(n, b)
         if d <= 1: break
         n //= d
     return n

src/spectrum/calculations/orders.py

@@ -14,9 +14,7 @@
    limitations under the License.
 
 """
-from math import gcd
-
-from spectrum.calculations.numeric import Integer, prod
+from spectrum.calculations.numeric import Integer, gcd, prod
 
 __author__ = 'Daniel Lytkin'
 

src/spectrum/calculations/semisimple.py

@@ -15,9 +15,9 @@
 
 """
 import itertools
-import math
 from functools import reduce
 
+from spectrum.calculations import numeric
 from spectrum.calculations.numeric import Integer
 from spectrum.calculations.set import MaximalBoundedSets, FullBoundedSets, BoundedSets
 from spectrum.tools.tools import ObjectCache
@@ -40,7 +40,7 @@ def __new__(cls, quotient=1, q=0, partition=None, signs=None,
         if signs is None:
             signs = []
         class_ = SpectraElement if verbose else int
-        return int.__new__(class_, quotient * reduce(math.lcm,
+        return int.__new__(class_, quotient * reduce(numeric.lcm,
                                                      (q ** ni + ei for (ni, ei) in zip(partition, signs)), 1))
 
     def __init__(self, quotient=1, q=0, partition=None, signs=None,
@@ -113,7 +113,7 @@ def lcm(self, other):
         """Returns lcm of this and other. 'q' must be the same. Quotients are
         multiplied.
         """
-        elem = int.__new__(SpectraElement, math.lcm(self, other))
+        elem = int.__new__(SpectraElement, numeric.lcm(self, other))
         quotient = self._quotient * other._quotient
         elem.__init__(quotient=quotient, q=self._q,
                       partition=list(self._partition) + list(other._partition),

src/spectrum/calculations/spectra.py

@@ -22,9 +22,9 @@
 
 """
 import itertools
-from math import gcd, lcm
 
 from spectrum.calculations import numeric
+from spectrum.calculations.numeric import gcd, lcm
 from spectrum.calculations.semisimple import MixedElements, SemisimpleElements, SpectraElement
 from spectrum.calculations.set import FullBoundedSets
 

src/tests/spectrum_tests/calculations/numeric_test.py

@@ -16,11 +16,11 @@
 """
 import itertools
 import unittest
-from math import gcd, lcm
 
-from spectrum.calculations.numeric import *
 from spectrum_tests.parametric import parametrized, parameters
 
+from spectrum.calculations.numeric import *
+
 __author__ = 'Daniel Lytkin'
 
 @parametrized

src/tests/spectrum_tests/calculations/semisimple_test.py

@@ -15,13 +15,14 @@
 
 """
 import itertools
-import math
 import unittest
 from functools import reduce
 
+from spectrum_tests.parametric import parameters, parametrized
+
+from spectrum.calculations import numeric
 from spectrum.calculations.partition import Partitions
 from spectrum.calculations.semisimple import SemisimpleElements, MixedElements, SpectraElement
-from spectrum_tests.parametric import parameters, parametrized
 
 __author__ = 'Daniel Lytkin'
 
@@ -35,10 +36,10 @@ def evaluate(q, ni, ei=-1):
     """
     try:
     # for integer ei
-        return reduce(math.lcm, (q ** n + ei for n in ni))
+        return reduce(numeric.lcm, (q ** n + ei for n in ni))
     except TypeError:
     # for sequence ei
-        return reduce(math.lcm, (q ** n + e for (n, e) in zip(ni, ei)))
+        return reduce(numeric.lcm, (q ** n + e for (n, e) in zip(ni, ei)))
 
 
 class Signs:

src/tests/spectrum_tests/modules/max_orders_test.py

@@ -14,12 +14,13 @@
    limitations under the License.
    
 """
-import math
 import unittest
 
+from spectrum_tests.parametric import parametrized, parameters
+
+from spectrum.calculations import numeric
 from spectrum.calculations.groups import ClassicalGroup
 from spectrum.modules import max_orders
-from spectrum_tests.parametric import parametrized, parameters
 
 __author__ = 'Daniel Lytkin'
 
@@ -46,5 +47,5 @@ def test_symplectic(self, n):
     @parameters(list(range(3, 100)))
     def test_symplectic_gcd(self, n):
         max_elems = max_orders.symplectic_2(n)
-        expected = math.gcd(*max_elems)
+        expected = numeric.gcd(*max_elems)
         self.assertEqual(expected, max_orders.symplectic_2_gcd(n))