Opened 10 years ago

Closed 3 years ago

#13932 closed defect (duplicate)

solve_right fails with floating-point matrices

Reported by: Volker Braun Owned by: jason, was
Priority: major Milestone: sage-duplicate/invalid/wontfix
Component: linear algebra Keywords:
Cc: Rob Beezer, Michael Orlitzky Merged in:
Authors: Reviewers: Michael Orlitzky
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Status badges

Description (last modified by Volker Braun)

As reported on https://groups.google.com/d/topic/sage-support/TjXY-Nl3PZI/discussion

sage: RF= RealField(52)
sage: Y=matrix(RF,2,2,1)
sage: A = matrix(RF,[[0.24,1,0],[1,0,0]])
sage: A.solve_right(Y)
    ValueError: matrix equation has no solutions

Though it decidedly does have solutions. solve_right() needs to implement a fuzzy check (or default to check=False) if the base field is not exact:

sage: sol = A.solve_right(Y, check=False)
sage: A*sol
[     1.00000000000000 -5.55111512312578e-17]
[    0.000000000000000      1.00000000000000]

Change History (8)

comment:1 Changed 10 years ago by Volker Braun

Description: modified (diff)

comment:2 Changed 9 years ago by Jeroen Demeyer

Milestone: sage-5.11sage-5.12

comment:3 Changed 9 years ago by For batch modifications

Milestone: sage-6.1sage-6.2

comment:4 Changed 9 years ago by For batch modifications

Milestone: sage-6.2sage-6.3

comment:5 Changed 8 years ago by For batch modifications

Milestone: sage-6.3sage-6.4

comment:6 Changed 3 years ago by Markus Wageringel

Cc: Michael Orlitzky added
Milestone: sage-6.4sage-duplicate/invalid/wontfix
Status: newneeds_review

Since #12406, the check is ignored for inexact rings, so this problem does not exist anymore. A doctest for this example has also been added in that ticket, so this ticket can be closed.

comment:7 Changed 3 years ago by Michael Orlitzky

Reviewers: Michael Orlitzky
Status: needs_reviewpositive_review

comment:8 Changed 3 years ago by Frédéric Chapoton

Resolution: duplicate
Status: positive_reviewclosed
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