Opened 13 years ago

Closed 13 years ago

Last modified 13 years ago

#1219 closed defect (duplicate)

bug in eigenspaces over CC

Reported by: wdj Owned by: was
Priority: major Milestone: sage-duplicate/invalid/wontfix
Component: linear algebra Keywords:
Cc: Merged in:
Authors: Reviewers:
Report Upstream: Work issues:
Branch: Commit:
Dependencies: Stopgaps:

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Description

Something funny is going on: 

sage: MS = MatrixSpace(CC, 2, 2)
sage: A = MS([[1,5],[3,-1]])
sage: A.eigenspaces()

[
(4.00000000000000, [
(1.00000000000000, 1.00000000000000)
]),
(-4.00000000000000, [

])
]
sage: A.eigenspaces()[0]

(4.00000000000000, [
(1.00000000000000, 1.00000000000000)
])
sage: A.eigenspaces()[1]

(-4.00000000000000, [

])
sage: MS = MatrixSpace(QQ, 2, 2)
sage: A = MS([[1,5],[3,-1]])
sage: A.eigenspaces()

[
(4, [
(1, 1)
]),
(-4, [
(1, -5/3)
])
]

I find it strange that eigenspaces works for QQ but not for the larger field CC.

Willam: The issue above is undoubtedly that there is no specialized implementation of matrices over CC. It's just completely generic code. So some generic echelon is going wrong.

Change History (3)

comment:1 Changed 13 years ago by mabshoff

  • Milestone changed from sage-2.10 to sage-2.9.1

comment:2 Changed 13 years ago by ncalexan

  • Resolution set to duplicate
  • Status changed from new to closed

#1706 and #2050 are essentially the same.

comment:3 Changed 13 years ago by mabshoff

  • Milestone changed from sage-2.10.2 to sage-duplicate/invalid
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