Done http://sagetrac.org/sage_trac/ticket/1219
On Nov 20, 2007 2:22 PM, William Stein <[EMAIL PROTECTED]> wrote: > > > On Nov 20, 2007 11:14 AM, David Joyner <[EMAIL PROTECTED]> wrote: > > > > Hi: > > > > 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. Makes me think > > the problem isn't with eigenspaces at all ... > > Should I create a trac item under linear algebra > > or ??? > > Yes make a trac ticket. 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. If you want something that actually works > very efficiently now, use CDF, which has the advantage that > it will scale to HUGE problems: > > > {{{id=0| > m = matrix(CDF,[[1,5],[3,-1]]) > }}} > > {{{id=1| > m.eigenspaces() > /// > ([4.0, -4.0], [Vector space of degree 2 and dimension 1 over Complex > Double Field > User basis matrix: > [ 0.707106781187 -0.514495755428], Vector space of degree 2 and > dimension 1 over Complex Double Field > User basis matrix: > [0.707106781187 0.857492925713]]) > }}} > > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://sage.math.washington.edu/sage/ and http://sage.scipy.org/sage/ -~----------~----~----~----~------~----~------~--~---