[GiNaC-list] psi (digamma) solving

[Vladimir V. Kisil]

On Tue, Mar 6, 2018 at 4:38 AM, Matej Usaj <m.usaj at utoronto.ca> wrote:

> Hi All,
>
> I'm trying to solve function that contains a call to psi (digamma) but
> my call to fsolve fails every time, ie:
>
> > f=psi(x/2)==0;
> psi(1/2*x)==0
> > fsolve(f,x,2.7,3.1);
> fsolve(): function does not evaluate numerically
>
> but I'd expect the result to be x~=2.923...
>
> Am I missing something here?
>

Can it be that psi function returns values in terms of the Euler constant?
Then you may need to make float evaluation wrapper for it.

Best wishes,
Vladimir
-- 
Vladimir V. Kisil                 http://www.maths.leeds.ac.uk/~kisilv/
  Book:     Geometry of Mobius Transformations     http://goo.gl/EaG2Vu
  Software: Geometry of cycles          http://moebinv.sourceforge.net/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.cebix.net/pipermail/ginac-list/attachments/20180306/ba37d461/attachment.html>