Hello, I would like to pick out individual eigenvectors of a matrix, and then be able to manipulate them as vectors. I tried the following:
---------------------------------------------------------------------- | Sage Version 3.2, Release Date: 2008-11-20 | | Type notebook() for the GUI, and license() for information. | ---------------------------------------------------------------------- sage: m=matrix([[1,2,2],[2,1,2],[2,2,1]]);m [1 2 2] [2 1 2] [2 2 1] sage: es = m.eigenvectors_right();es [(5, [ (1, 1, 1) ], 1), (-1, [ (1, 0, -1), (0, 1, -1) ], 2)] sage: eval, evec, degen = es[0];evec [ (1, 1, 1) ] But if I try to act with the matrix m on the eigenvector evec, there is a problem: sage: m*evec --------------------------------------------------------------------------- TypeError Traceback (most recent call last) /Users/rafael/<ipython console> in <module>() /Applications/sage-3.2/local/lib/python2.5/site-packages/sage/ structure/element.so in sage.structure.element.Matrix.__mul__ (sage/ structure/element.c:11189)() /Applications/sage-3.2/local/lib/python2.5/site-packages/sage/ structure/coerce.so in sage.structure.coerce.CoercionModel_cache_maps.bin_op (sage/structure/ coerce.c:5782)() TypeError: unsupported operand parent(s) for '*': 'Full MatrixSpace of 3 by 3 dense matrices over Integer Ring' and 'Category of sequences in Vector space of degree 3 and dimension 1 over Rational Field User basis matrix: [1 1 1]' On the other hand, the following does work: sage: w=vector([1, 1, 1]);w (1, 1, 1) sage: m*w (5, 5, 5) So it seems I need to convert evec, which is a sequence, to a vector. Is there a way to do this (other than retyping as above)? Many thanks! Rafael --~--~---------~--~----~------------~-------~--~----~ 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://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
