Thanks for this hint. If I find revelant example, I will post them in this discussion.
2014-10-31 17:38 GMT+01:00 Aaron Meurer <[email protected]>: > On Fri, Oct 31, 2014 at 6:37 AM, Christophe Bal <[email protected]> > wrote: > > Thanks for the answers. > > > > Maybe integration will be a good candidate. When I talk about formal > output, > > I think of special case where the formula given is correct but certainl > not > > the one a human will see first. > > I see. I was thinking more of cases where the human wouldn't see how > to solve it at all. > > A possible idea here is integrals using square roots. Humans tend to > make simplifications on square roots which are not true in general, > leading to "simpler" output, whereas computer algebra systems try to > be more cautious about them. For instance, sqrt(1/x) != 1/sqrt(x). > > Aaron Meurer > > > > > One day, a student had shown me an integral which was evaluate by its > formal > > calculator to a formula containing arctan whereas my solution do not use > it, > > and was more simple. The problem is that I have not noted this example... > > > > Maybe solving some polynomial of degree 3 can give such "complicated" > > formulas that a human would not use. > > > > Christophe BAL > > > > 2014-10-30 23:53 GMT+01:00 Richard Fateman <[email protected]>: > >> > >> There are even simpler examples. For instance, some systems multiply > >> polynomials by some evaluation/interpolation scheme in finite fields. Or > >> by FFT > >> or by so-called Karatsuba or Cooke-Toom methods or a Kronecker method > >> evaluating a polynomial to a single huge integer... > >> > >> Risch integration is certainly another one. > >> > >> > >> On Wednesday, October 29, 2014 3:40:58 AM UTC-7, Christophe Bal wrote: > >>> > >>> Hello. > >>> > >>> I'm looking for formal outputs that are not calculated as a human can > do > >>> (this is for a free french "book"). Do you know such kind of examples ? > >>> > >>> Christophe BAL > >>> > >>> PS : this questions has been posted on both Sage and Sympy lists. > >> > >> -- > >> You received this message because you are subscribed to the Google > Groups > >> "sympy" group. > >> To unsubscribe from this group and stop receiving emails from it, send > an > >> email to [email protected]. > >> To post to this group, send email to [email protected]. > >> Visit this group at http://groups.google.com/group/sympy. > >> To view this discussion on the web visit > >> > https://groups.google.com/d/msgid/sympy/a2c48c91-3bc3-4761-bef7-7a8bdebc7297%40googlegroups.com > . > >> > >> For more options, visit https://groups.google.com/d/optout. > > > > > > -- > > You received this message because you are subscribed to the Google Groups > > "sympy" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to [email protected]. > > To post to this group, send email to [email protected]. > > Visit this group at http://groups.google.com/group/sympy. > > To view this discussion on the web visit > > > https://groups.google.com/d/msgid/sympy/CAAb4jGmGUqW1vGBkYLieOYhBGJT%3DOn7nfZDyHVNFW524%3DGfN7w%40mail.gmail.com > . > > > > For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/sympy. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/CAKgW%3D6JH_tCkVtKsmFxcJ4Ucbajc8pmxBnzzr3dtNTiWUhMpAg%40mail.gmail.com > . > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAAb4jGmpfEm4fV3CAJDvXZBZZ%2BzDdtxAeU3tVu1w%3Dc5_52xhKg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
