#4623: x^2 is wrong in RealIntervalField
------------------------------+---------------------------------------------
Reporter: zimmerma | Owner: somebody
Type: defect | Status: new
Priority: major | Milestone: sage-3.2.1
Component: basic arithmetic | Keywords:
------------------------------+---------------------------------------------
{{{
sage: R=RealIntervalField(53)
sage: x=R(-1,2)
sage: xx=x^2
sage: xx.lower(), xx.upper()
(-2.00000000000000, 4.00000000000000)
}}}
The result should be (0, 4) instead, since for -1 <= x <= 2, we have 0 <=
x^2 <= 4.
(Of course (-2, 4) is a correct enclosure, but any specialist of interval
arithmetic
will consider that as a real bug.)
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/4623>
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
-~----------~----~----~----~------~----~------~--~---
