alex wrote: > yes, this is what i want ! > > BUT i cant compute the eigenvectors symbolically within SAGE. > So for example > > A.eigenvectors() > > gives the error: > AttributeError: 'sage.matrix.matrix_symbolic_dense.Matrix_symbolic_' > object has no attribute 'eigenvectors' > > how can i now compute those eigenvectors within SAGE or with the > MAXIMA interface ?
Searching the google interface to sage-support for "symbolic eigenvectors" yields this message from a few days ago. Right now, calculating eigenvectors of symbolic matrices is a bit different than other matrices; hopefully this will be corrected soon. http://groups.google.com/group/sage-support/browse_thread/thread/4370a886918b0f14/a7578c228b204558?lnk=gst&q=symbolic+eigenvectors#a7578c228b204558 Thanks, Jason > Thank you very much ! > > ___________________________________________________ > On Mar 9, 6:48 pm, Robert Bradshaw <rober...@math.washington.edu> > wrote: >> On Mar 9, 2009, at 4:44 AM, David Joyner wrote: >> >> >> >>> On Sun, Mar 8, 2009 at 1:43 PM, alex >>> <alessandro.bernardini.1...@gmail.com> wrote: >>>> How can i compute the matrix multiplication (product) of two symbolic >>>> matrices in sage ? >>>> I have tried: >>>> A = maxima("matrix ([a, b], [c, d])") >>>> AI= A.invert() >>>> and >>>> A * AI >>>> gives >>>> matrix([a*d/(a*d-b*c),-b^2/(a*d-b*c)],[-c^2/(a*d-b*c),a*d/(a*d-b*c)]) >>> Do you want the following? >>> sage: a,b,c,d = var("a,b,c,d") >>> sage: A = matrix ([[a, b], [c, d]]) >>> sage: AI = A.inverse() >>> sage: P = A*AI; P >>> [a*d/(a*d - b*c) - b*c/(a*d - b*c) 0] >>> [ 0 a*d/(a*d - b*c) - b*c/(a*d - b*c)] >> sage: P.simplify_rational() >> >> [1 0] >> [0 1] > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
