#4214: [with patch, needs work] elliptic_logarithm gives inaccurate answers
---------------------------+------------------------------------------------
Reporter: AlexGhitza | Owner: AlexGhitza
Type: defect | Status: new
Priority: major | Milestone: sage-3.1.3
Component: number theory | Resolution:
Keywords: |
---------------------------+------------------------------------------------
Changes (by GeorgSWeber):
* summary: [with patch, needs review] elliptic_logarithm gives
inaccurate answers => [with patch, needs work]
elliptic_logarithm gives inaccurate answers
Comment:
Hi Alex,
unfortunately, the patch does not work yet. This is what I get before
applying the patch:
{{{
sage -t -long
devel/sage/sage/schemes/elliptic_curves/ell_point.py**********************************************************************
File "/Users/georgweber/Public/sage/sage-3.1.3.alpha3/tmp/ell_point.py",
line 1103:
sage: P.elliptic_logarithm(precision=55)
Expected:
0.2735052644156991
Got:
0.2735052671206336
**********************************************************************
File "/Users/georgweber/Public/sage/sage-3.1.3.alpha3/tmp/ell_point.py",
line 1105:
sage: P.elliptic_logarithm() # 100 bits
Expected:
0.27656204014107100870071052662
Got:
0.27656204014107100870070982517
**********************************************************************
1 items had failures:
2 of 20 in __main__.example_33
***Test Failed*** 2 failures.
For whitespace errors, see the file
/Users/georgweber/Public/sage/sage-3.1.3.alpha3/tmp/.doctest_ell_point.py
[35.2 s]
exit code: 1024
----------------------------------------------------------------------
The following tests failed:
sage -t -long devel/sage/sage/schemes/elliptic_curves/ell_point.py
Total time for all tests: 35.2 seconds
}}}
But after applying the patch (to vanilla Sage 3.1.3alpha3 on my Intel Mac
OS X 10.4), I still get:
{{{
sage -t -long
devel/sage/sage/schemes/elliptic_curves/ell_point.py**********************************************************************
File "/Users/georgweber/Public/sage/sage-3.1.3.alpha3/tmp/ell_point.py",
line 1120:
sage: P.elliptic_logarithm(algorithm='sage') # 100 bits
Expected:
0.27656204014107100870071052662
Got:
0.27656204014107100870070982517
**********************************************************************
1 items had failures:
1 of 21 in __main__.example_33
***Test Failed*** 1 failures.
For whitespace errors, see the file
/Users/georgweber/Public/sage/sage-3.1.3.alpha3/tmp/.doctest_ell_point.py
[28.4 s]
exit code: 1024
----------------------------------------------------------------------
The following tests failed:
sage -t -long devel/sage/sage/schemes/elliptic_curves/ell_point.py
Total time for all tests: 28.4 seconds
}}}
Thus the patch got one failure away, but the other pertains.
Maybe just use dots for the time being (see the following line) there in
the doctest,
as even these fewer digits already display what you want to show (accuracy
problem
of the Sage internal algorithm)?
{{{
0.2765620401410710087...
}}}
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/4214#comment:4>
Sage <http://sagemath.org/>
Sage - Open Source Mathematical Software: Building the Car Instead of
Reinventing the Wheel
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en
-~----------~----~----~----~------~----~------~--~---
