[Python-checkins] cpython: Issue #11188: In log2 tests, create powers of 2 using ldexp(1, n) instead of

[mark.dickinson]

http://hg.python.org/cpython/rev/1f23d63b578c
changeset:   69979:1f23d63b578c
user:        Mark Dickinson <mdickinson at enthought.com>
date:        Mon May 09 14:02:45 2011 +0100
summary:
  Issue #11188: In log2 tests, create powers of 2 using ldexp(1, n) instead of the less reliable 2.0**n.

files:
  Lib/test/test_math.py |  4 ++--
  1 files changed, 2 insertions(+), 2 deletions(-)


diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py
--- a/Lib/test/test_math.py
+++ b/Lib/test/test_math.py
@@ -653,8 +653,8 @@
     def testLog2(self):
         self.assertRaises(TypeError, math.log2)
         # Check that we get exact equality for log2 of powers of 2.
-        actual = [math.log2(2.0**n) for n in range(-324, 1024)]
-        expected = [float(n) for n in range(-324, 1024)]
+        actual = [math.log2(math.ldexp(1.0, n)) for n in range(-1074, 1024)]
+        expected = [float(n) for n in range(-1074, 1024)]
         self.assertEqual(actual, expected)
 
         # Check some integer values

-- 
Repository URL: http://hg.python.org/cpython