#2350 Summation still works with endpoint zero

None
closed
nobody
5
2013-02-08
2012-02-01
Anonymous
No

Maxima 5.26.0 http://maxima.sourceforge.net
using Lisp SBCL 1.0.24
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) load(simplify_sum);
(%o1) /Users/.../maxima-5.26.0/share/contrib/solve_re\ c/simplify_sum.mac
(%i2) simplify_sum(sum(1/x*(-1)^x,x,1,inf));

(%o2) - log(2)
(%i3) simplify_sum(sum(1/x*(-1)^x,x,0,inf));

(%o3) - log(2)

You'll notice that the second sum would have 1/0 as a term, though.

Originally reported by dkrenn at http://trac.sagemath.org/sage_trac/ticket/12410.

Discussion

  • Andrej Vodopivec

    • status: open --> closed
    • milestone: --> None
     
  • Andrej Vodopivec

    Fixed in git:

    (%i9) simplify_sum(sum(1/x(-1)^x,x,1,inf));
    (%o9) -log(2)
    (%i10) simplify_sum(sum(1/x
    (-1)^x,x,0,inf));
    Zero to negative power computed.
    0: simp_gen_harmonic_number(exp=1,x=-1)(simplify_sum.mac line 825)
    1: ratfun_to_psi(ratfun=-1/(2*?g4522-2),var=?g4522,lo=1,hi=inf)
    2: simplify_sum(expr='sum((-1)^x/x,x,0,inf))(simplify_sum.mac line 250)
    -- an error. To debug this try: debugmode(true);

     

Get latest updates about Open Source Projects, Conferences and News.

Sign up for the SourceForge newsletter:





No, thanks