#17728: Infinity norm of real interval vectors
------------------------------+----------------------------
Reporter: f.poloni | Owner:
Type: PLEASE CHANGE | Status: new
Priority: major | Milestone: sage-6.5
Component: linear algebra | Keywords:
Merged in: | Authors:
Reviewers: | Report Upstream: N/A
Work issues: | Branch:
Commit: | Dependencies:
Stopgaps: |
------------------------------+----------------------------
As documented in
http://www.sagemath.org/doc/reference/rings_numerical/sage/rings/real_mpfi.html#sage.rings.real_mpfi.RealIntervalFieldElement.max,
`max(I,J)` does not do the correct thing for real intervals, and
`I.max(J)` has to be used instead.
When computing the infinity norm of a vector of real intervals, the wrong
version of `max` gets used, though:
{{{
sage: x = RIF(1,2)
sage: y = RIF(0,4)
sage: print "Wrong max: ", max(x,y).endpoints()
Wrong max: (1.00000000000000, 2.00000000000000)
sage: print "Correct max: ", x.max(y).endpoints()
Correct max: (1.00000000000000, 4.00000000000000)
sage:
sage: v = vector([x,y])
sage: print "Computed infinity norm: ", v.norm(Infinity).endpoints()
Computed infinity norm: (1.00000000000000, 2.00000000000000)
}}}
--
Ticket URL: <http://trac.sagemath.org/ticket/17728>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/d/optout.
