On 4/26/07, Jonathan William Bober <[EMAIL PROTECTED]> wrote: >> There also seem to be some other issues which come from maxima. One > example is > > sage: print B > sqrt(3) I 1 > ---------- - - > 2 2 > sage: bool(B^3 == 1) > False > sage: bool(expand(B^3) == 1) > True
That's just how maxima works. It can't, in general, test equality or not with certainty, and errors on the side of caution. This is I think a really hard problem in general... I could make SAGE's bool try expanding, simplifying, etc. first (??) > > A stranger example is > > sage: print A > I pi > ------ > 5 > e > sage: print A*A*A*A*A*A*A*A*A*A > - (- "*"()) This is intriguing. What's happening is that SAGE is sending the following to maxima to be evaluated, since we haven't optimized yet much minimizing th enumber of parenthesis, etc: (((((((((exp(((%i) * (%pi)) / (5))) * (exp(((%i) * (%pi)) / (5)))) * (exp(((%i) * (%pi)) / (5)))) * (exp(((%i) * (%pi)) / (5)))) * (exp(((%i) * (%pi)) / (5)))) * (exp(((%i) * (%pi)) / (5)))) * (exp(((%i) * (%pi)) / (5)))) * (exp(((%i) * (%pi)) / (5)))) * (exp(((%i) * (%pi)) / (5)))) * (exp(((%i) * (%pi)) / (5))) And, directly in MAXIMA, if you past the above, you get nonsense -- so I think there is a bug in Maxima itself: $ maxima Maxima 5.11.0 http://maxima.sourceforge.net Using Lisp CLISP 2.41 (2006-10-13) Distributed under the GNU Public License. See the file COPYING. Dedicated to the memory of William Schelter. This is a development version of Maxima. The function bug_report() provides bug reporting information. (%i1) (((((((((exp(((%i) * (%pi)) / (5))) * (exp(((%i) * (%pi)) / (5)))) * (exp(((%i) * (%pi)) / (5)))) * (exp(((%i) * (%pi)) / (5)))) * (exp(((%i) * (%pi)) / (5)))) * (exp(((%i) * (%pi)) / (5)))) * (exp(((%i) * (%pi)) / (5)))) * (exp(((%i) * (%pi)) / (5)))) * (exp(((%i) * (%pi)) / (5)))) * (exp(((%i) * (%pi)) / (5))) ; (%o1) - (- "*"()) (%i2) I'll investigate reducing the number of spurious parenthesis and see if this helps. > I've never used computer algebra systems much before, so perhaps these > types of limitations are common and I just don't know about it. Either > way, except for perhaps > > - (- "*"()) > > these problems seem to stem from maxima, so there is unlikely to be a > simple solution. I don't know where the weird - (- "*"()) comes from, > though - it seems to be ok in maxima: > > (%i52) A; > %i %pi > ------ > 5 > (%o52) %e > (%i53) A*A*A*A*A*A*A*A*A*A; > (%o53) 1 --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@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-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
