Changes between Initial Version and Version 2 of Ticket #12688


Ignore:
Timestamp:
03/18/12 19:14:47 (10 years ago)
Author:
rbeezer
Comment:

See some discussion on #12541.

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  • Ticket #12688

    • Property Cc novoselt added
    • Property Priority changed from major to minor
    • Property Type changed from defect to enhancement
    • Property Summary changed from Span method allows setting incompatible base ring, despite 'check=True' to Improve documentation of span method
  • Ticket #12688 – Description

    initial v2  
    1 I discovered this while working on #12541.  Documentation says the `check` will "coerce entries of gens into base field."  This does not appear to be happening, and should. 
     1I discovered this while working on #12541.  Documentation says the `check` will "coerce entries of gens into base field."  This does not appear to be happening, and should.  (Edit: this is an integral span of rational vectors, a construction that is intended, so improving the documentation might be in order.)
    22
    3 First example is the root problem - second just shows that the `check` flag seems ineffectual.  I haven't looked at the code yet.
    43
    54{{{
     
    87Echelon basis matrix:
    98[  1 1/2]
    10 sage: (QQ^2).span(gens=[vector(QQ, [1,1/2])], base_ring=ZZ, check=False)
    11 Free module of degree 2 and rank 1 over Integer Ring
    12 Echelon basis matrix:
    13 [  1 1/2]
    149}}}