On Mon, 11 Dec 2006 17:58:39 -0800, David Joyner <[EMAIL PROTECTED]> wrote:
> > I'm working on tut.tex in sage 1.5 alpha12. I've made several > fixes but have run into some questions. Alex Clemesha is also. We're coordinating our work in the irc chatroom and at http://sage.math.washington.edu:9001/1.5 > 1. The command > R = ElementaryFunctionRing(QQ,"t"); R > doesn't work. Did you remove that module? Yes. Elemantary functions is so far from obeying a number of the SAGE structure rules that I've temporarily removed it until it can be updated (which will take a lot of work). > 2. The command > sage: MS = MatrixSpace(GF(7),2,2) > sage: g = MS([[5, 1], [4, 1]]) > sage: g.eigenvalues() > doesn't work. Did you remove eigenvalues and eigenvectors? They are replaced by eigenspaces, which gives both. > 3. The command > sage: A = maxima("A: matrix ([1, 0, 0], [1, -1, 0], [1, 3, -2])") > sage: eigA = A.eigenvectors() > sage: V = VectorSpace(QQ,3) > sage: eigA > [[[ - 2, - 1,1],[1,1,1]],[0,0,1],[0,1,3],[1,1/2,5/6]] > sage: v1 = V(sage_eval(str(eigA[1]))); lambda1 = > sage_eval(str(eigA[0][0][0])) > sage: v2 = V(sage_eval(str(eigA[2]))); lambda2 = > sage_eval(str(eigA[0][0][1])) > sage: v3 = V(sage_eval(str(eigA[3]))); lambda3 = > sage_eval(str(eigA[0][0][2])) > sage: M = MatrixSpace(QQ,3,3) > sage: AA = M([[1,0,0],[1, - 1,0],[1,3, - 2]]) > sage: AA*v1 == lambda1*v1 > True > sage: AA*v2 == lambda2*v2 > True > sage: AA*v3 == lambda3*v3 > True > works. However, it seems overly tricky to me. The previous version didn't > require such gymnastics to convert a "Maxima element" (even if it > is an integer) to a SAGE element. Is it okay to leave this as above? Get rid of all that. For eigenvectors, one shouldn't use maxima. > 4. The maxima output has changed: > sage: maxima.eval("f:bessel_y (v, w)") > '?%bessel_y(v,w)' > (it used to be 'bessel_y(v,w)'). Is this a consequence of the new > version of Maxima? Do you want that? The extra "?%" is confusing. This is a consequence of the new version of maxima. I don't know what to do about it. It's their fault. > > 5. This seems to indicate a bug: > sage: MS = MatrixSpace(GF(7), 2) > sage: sage: gens = [MS([[1,0],[-1,1]]),MS([[1,1],[0,1]])] > sage: sage: G = MatrixGroup(gens) > sage: G.conjugacy_class_representatives() > [ > [1 0] > [0 1], > [6 0] > [0 6] > ] > It worked correctly in the previous version of SAGE. I'll look into this. > 6. The module Numeric does not seem to exist: > sage: import Numeric > --------------------------------------------------------------------------- > <type 'exceptions.ImportError'> Traceback (most recent call > last) > /home/wdj/sagefiles/sage-1.5.alpha12/devel/doc-1.5.alpha12/tut/<ipython > console> in <module>() > <type 'exceptions.ImportError'>: No module named Numeric > Are you leaving Numeric out? I vaguely remember a discussion about > numeric/numpy/scipy but I've forgotten what the decision was. I think > it used to be a standard package. > > +++++++++++++++++++++++++++++++++++++++ Numeric is being replaced by numpy. --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
