Opened 10 years ago

Closed 3 years ago

# solve_right fails with floating-point matrices

Reported by: Owned by: Volker Braun jason, was major sage-duplicate/invalid/wontfix linear algebra Rob Beezer, Michael Orlitzky Michael Orlitzky N/A

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]

### comment:1 Changed 10 years ago by Volker Braun

Description: modified (diff)

### comment:2 Changed 9 years ago by Jeroen Demeyer

Milestone: sage-5.11 → sage-5.12

### comment:3 Changed 9 years ago by For batch modifications

Milestone: sage-6.1 → sage-6.2

### comment:4 Changed 9 years ago by For batch modifications

Milestone: sage-6.2 → sage-6.3

### comment:5 Changed 8 years ago by For batch modifications

Milestone: sage-6.3 → sage-6.4

### comment:6 Changed 3 years ago by Markus Wageringel

Cc: Michael Orlitzky added sage-6.4 → sage-duplicate/invalid/wontfix new → needs_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 needs_review → positive_review

### comment:8 Changed 3 years ago by Frédéric Chapoton

Resolution: → duplicate positive_review → closed
Note: See TracTickets for help on using tickets.