[patch proposed, positive review to fix] ssmod.py failure

[gfurnish]

sage -t  devel/sage/sage/modular/ssmod/ssmod.py             **********************************************************************
File "/home/x/build/sage-3.0.alpha1/tmp/ssmod.py", line 14:
    sage: D[:3]
Expected:
    [
    (Vector space of degree 33 and dimension 1 over Finite Field of size 97
    Basis matrix:
    [ 0  0  0  1 96 96  1 96 96  0  2 96 96  0  1  0  1  2 95  0  1  1  0  1  0 95  0 96 95  1 96  0  2], True),
    (Vector space of degree 33 and dimension 1 over Finite Field of size 97
    Basis matrix:
    [ 0  1 96 75 16 81 22 17 17  0  0 80 80  1 16 40 74  0  0 96 81 23 57 74  0  0  0 24  0 23 73  0  0], True),
    (Vector space of degree 33 and dimension 1 over Finite Field of size 97
    Basis matrix:
    [ 0  1 96 90 90  7  7  6 91  0  0 91  6 13  7  0 91  0  0 84 90  6  0  6  0  0  0 90  0 91  7  0  0], True)
    ]
Got:
    [
    (Vector space of degree 33 and dimension 0 over Finite Field of size 97
    Basis matrix:
    [], True),
    (Sparse vector space of degree 33 and dimension 6 over Finite Field of size 97
    Basis matrix:
    [ 1  0  0  0  0  0 42 22 77 61  8 76 27 95 75 81 24 22 61 78  3 95 44 26 63 31 47 61 67 24 26 49 91]
    [ 0  1  0  0  0  0 63 79 96 61 54 21 37 39 70 51  3 68 91 54 33 20 61 96 72 23 62 45 87 24 66 31 88]
    [ 0  0  1  0  0  0  0 19 95 33 67 91 19  0 29 78 70 37 48 72 37 62 45 72 40 57 46 95 29 50 30  6 17]
    [ 0  0  0  1  0  0 20 57 50 17 95 67  2 88 67 57  1 41 84 44 90 96 31 34  3 46 13 52 96 94 62 77 94]
    [ 0  0  0  0  1  0 50  6 38 38 50 31 23 32 68 45 26  9 66  6 51 31 50 53 17 29 89 53 70 24 44 27 30]
    [ 0  0  0  0  0  1 20  8 77 51 41 25  7 63 75  2 86 20 23  0 29 77 13 26 45 10 38 41 66 68 40 49 15], True),
    (Sparse vector space of degree 33 and dimension 8 over Finite Field of size 97
    Basis matrix:
    [ 1  0  0  0  0  0  0  0 23 48 44 88  8 82 60 13 35 15 74 59 18 78 42 16 12 91 13  8 19 28 41 48 31]
    [ 0  1  0  0  0  0  0  0 83 78 55 39 17 91 90 29 85 89  3 53 15 47  8 25 79 40 82 79 24 33 45 29 70]
    [ 0  0  1  0  0  0  0  0 69 74 21 95 41  9 80 89  6 33 17 23 94 73 65 65 61 91 77 48 32 42  4 23 46]
    [ 0  0  0  1  0  0  0  0 43 36  6 41  4 80 73 63 38 94 33 94 71 62 93 41 83 90 21 58 57 94 79  4 88]
    [ 0  0  0  0  1  0  0  0 87 26 91 28 67 79 78 79 62 75 25 73 24 92  5 69 17  5 67 41 65  5  0 87 57]
    [ 0  0  0  0  0  1  0  0 37  8 88  0 56 62 67 80 82  5 62 38 64  5 14 52 64 77 77 51 79 57 34 67  6]
    [ 0  0  0  0  0  0  1  0 46  1 43 61 76 30 91 96 77 15 43 37 90 84 70 68 24 84 34 85 46 13 10 65  9]
    [ 0  0  0  0  0  0  0  1 78 41 40 60 52 57 13 88 90 96 29 78 95 77 16 69 72 13 85  8  3 40 19 20 53], True)
    ]
**********************************************************************
File "/home/x/build/sage-3.0.alpha1/tmp/ssmod.py", line 26:
    sage: len(D)
Expected:
    9
Got:
    4

This is a heisenbug. It works some of the time. It also sometimes spits out "itere dependant intercale" at random. Test machine is a 64 bit gentoo install with 4.2.3 gcc

[cpernet]

trivial patch to revert to LUK charpoly method

[cpernet]

I reverted the default LinBox? method to LUK which is a slower on large matrices but much safer. This fix is temporary waiting, for me to investigate the real bug in the ArithProg? method. I put an updated spkg at  http://sage.math.washington.edu/home/tabbott/linbox-1.1.5p1.spkg

[cpernet]

Sorry I messed up the address:  http://sage.math.washington.edu/home/pernet/linbox-1.1.5p1.spkg

[gfurnish]

Changing the method to LUK does indeed fix the failure, although it is important to note that 2804.patch is messed up and doesn't do this at all.

[mabshoff]

Replying to gfurnish:

Changing the method to LUK does indeed fix the failure, although it is important to note that 2804.patch is messed up and doesn't do this at all.

I will check out the updated LinBox?.spkg and make sure it has the right fix in it. Otherwise I will apply the patch manually.

Cheers,

Michael

[gfurnish]

Positive review to the change to LUK

[mabshoff]

Merged in Sage 3.0.alpha2