Opened 14 years ago

Closed 13 years ago

error inverting matrix over RQDF

Reported by: Owned by: mhansen was major sage-duplicate/invalid/wontfix linear algebra

Description

I've attached b.sobj which you can load to reproduce the error.

```sage: ~b
---------------------------------------------------------------------------
<type 'exceptions.ZeroDivisionError'>     Traceback (most recent call last)

/home/mike/<ipython console> in <module>()

/home/mike/matrix0.pyx in sage.matrix.matrix0.Matrix.__invert__()

<type 'exceptions.ZeroDivisionError'>: self is not invertible
sage: c = b.change_ring(RDF)
sage: ~c

[ 0.0277777777778  0.0277777777778  0.0277777777778  0.0277777777778  0.0277777777778  0.0277777777778]
[  0.111111111111  -0.111111111111  0.0555555555556 -0.0555555555556  0.0555555555556 -0.0555555555556]
[             0.0              0.0  0.0962250448649  0.0962250448649 -0.0962250448649 -0.0962250448649]
[            -0.0             -0.0  0.0962250448649 -0.0962250448649 -0.0962250448649  0.0962250448649]
[  0.111111111111   0.111111111111 -0.0555555555556 -0.0555555555556 -0.0555555555556 -0.0555555555556]
[ 0.0277777777778 -0.0277777777778 -0.0277777777778  0.0277777777778 -0.0277777777778  0.0277777777778]

```

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 mhansen

This is due to the following:

```sage: b = load('/home/mike/Desktop/b.sobj')
sage: A = b.augment(b.parent().identity_matrix())
sage: B = A.echelon_form()
sage: B[5,5]
1.000000000000000000000000000000000000000000000000000000000000000
sage: B[5,5] == 1
False
```

comment:3 Changed 13 years ago by mabshoff

This ought to be solved. Maybe it is fodder fir Bug Day 8.

Cheers,

Michael

comment:4 Changed 13 years ago by mabshoff

• Milestone changed from sage-3.2.1 to sage-duplicate/invalid/wontfix
• Resolution set to wontfix
• Status changed from new to closed

Wontfix since we will remove RQDF - see #3762.

Cheers,

Michael

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