Excellent, yes, this solution will work for me! Thanks for your swift reply!
On Jan 15, 11:12 pm, Jason Grout <jason-s...@creativetrax.com> wrote: > c mullan wrote: > > Hi, > > > Suppose I compute the Jordan Normal Form of a matrix, > > > A.jordan_form() > > > Then in the output I can see that the block sizes are indicated (by > > subdivide='True'), but I can't extract this information. I would like > > a list of block sizes, (e.g. [2,2,1,1,1] for a 7x7 matrix). > > > I cannot figure out how to do this, any ideas? > > sage: a = matrix(ZZ,4,[1, 0, 0, 0, 0, 1, 0, 0, 1, -1, 1, 0, 1, -1, 1, 2]) > sage: b=a.jordan_form() > sage: b > > [2|0 0|0] > [-+---+-] > [0|1 1|0] > [0|0 1|0] > [-+---+-] > [0|0 0|1] > sage: b.subdivisions > ([0, 1, 3, 4], [0, 1, 3, 4]) > > That will give you the indices of the subdivisions, for any subdivided > matrix. You can then calculate the jordan block sizes from that by > subtracting each pair of numbers. > > Alternatively, maybe there could be something in the jordan form > function that returns the jordan block sizes for each of the eigenvalues... > > Jason --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
