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| author | Mark Dickinson <dickinsm@gmail.com> | 2010-06-13 10:52:38 (GMT) |
|---|---|---|
| committer | Mark Dickinson <dickinsm@gmail.com> | 2010-06-13 10:52:38 (GMT) |
| commit | bcdf9da26581266a35a2c7adc835c4580177c1ec (patch) | |
| tree | 8223c5a8f1faa149c69305f68e97c463c1369a19 /Lib | |
| parent | c6f1396be0a09d44de4ea8415c72c947521229d7 (diff) | |
| download | cpython-bcdf9da26581266a35a2c7adc835c4580177c1ec.zip cpython-bcdf9da26581266a35a2c7adc835c4580177c1ec.tar.gz cpython-bcdf9da26581266a35a2c7adc835c4580177c1ec.tar.bz2 | |
Merged revisions 81967 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
........
r81967 | mark.dickinson | 2010-06-13 11:50:29 +0100 (Sun, 13 Jun 2010) | 4 lines
Issue #8986: erfc was raising OverflowError on Linux for arguments in
the (approximate) range (-27.3, 30.0), as a result of an escaped errno
value.
........
Diffstat (limited to 'Lib')
| -rw-r--r-- | Lib/test/math_testcases.txt | 38 | ||||
| -rw-r--r-- | Lib/test/test_math.py | 9 |
2 files changed, 47 insertions, 0 deletions
diff --git a/Lib/test/math_testcases.txt b/Lib/test/math_testcases.txt index 21730df..be1a49f 100644 --- a/Lib/test/math_testcases.txt +++ b/Lib/test/math_testcases.txt @@ -84,6 +84,25 @@ erf0041 erf 1e16 -> 1.0 erf0042 erf -1e150 -> -1.0 erf0043 erf 1.7e308 -> 1.0 +-- Issue 8986: inputs x with exp(-x*x) near the underflow threshold +-- incorrectly signalled overflow on some platforms. +erf0100 erf 26.2 -> 1.0 +erf0101 erf 26.4 -> 1.0 +erf0102 erf 26.6 -> 1.0 +erf0103 erf 26.8 -> 1.0 +erf0104 erf 27.0 -> 1.0 +erf0105 erf 27.2 -> 1.0 +erf0106 erf 27.4 -> 1.0 +erf0107 erf 27.6 -> 1.0 + +erf0110 erf -26.2 -> -1.0 +erf0111 erf -26.4 -> -1.0 +erf0112 erf -26.6 -> -1.0 +erf0113 erf -26.8 -> -1.0 +erf0114 erf -27.0 -> -1.0 +erf0115 erf -27.2 -> -1.0 +erf0116 erf -27.4 -> -1.0 +erf0117 erf -27.6 -> -1.0 ---------------------------------------- -- erfc: complementary error function -- @@ -127,6 +146,25 @@ erfc0051 erfc 1e16 -> 0.0 erfc0052 erfc -1e150 -> 2.0 erfc0053 erfc 1.7e308 -> 0.0 +-- Issue 8986: inputs x with exp(-x*x) near the underflow threshold +-- incorrectly signalled overflow on some platforms. +erfc0100 erfc 26.2 -> 1.6432507924389461e-300 +erfc0101 erfc 26.4 -> 4.4017768588035426e-305 +erfc0102 erfc 26.6 -> 1.0885125885442269e-309 +erfc0103 erfc 26.8 -> 2.4849621571966629e-314 +erfc0104 erfc 27.0 -> 5.2370464393526292e-319 +erfc0105 erfc 27.2 -> 9.8813129168249309e-324 +erfc0106 erfc 27.4 -> 0.0 +erfc0107 erfc 27.6 -> 0.0 + +erfc0110 erfc -26.2 -> 2.0 +erfc0111 erfc -26.4 -> 2.0 +erfc0112 erfc -26.6 -> 2.0 +erfc0113 erfc -26.8 -> 2.0 +erfc0114 erfc -27.0 -> 2.0 +erfc0115 erfc -27.2 -> 2.0 +erfc0116 erfc -27.4 -> 2.0 +erfc0117 erfc -27.6 -> 2.0 --------------------------------------------------------- -- lgamma: log of absolute value of the gamma function -- diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py index 6c44435..6c07c88 100644 --- a/Lib/test/test_math.py +++ b/Lib/test/test_math.py @@ -1042,6 +1042,15 @@ class MathTests(unittest.TestCase): accuracy_failure = acc_check(expected, got, rel_err = 5e-15, abs_err = 5e-15) + elif fn == 'erfc': + # erfc has less-than-ideal accuracy for large + # arguments (x ~ 25 or so), mainly due to the + # error involved in computing exp(-x*x). + # + # XXX Would be better to weaken this test only + # for large x, instead of for all x. + accuracy_failure = ulps_check(expected, got, 2000) + else: accuracy_failure = ulps_check(expected, got, 20) if accuracy_failure is None: |