PolyGamma function of order n

From: <andreyk1_at_post.tau.ac.il>
Date: Wed, 11 Apr 2007 16:03:37 +0300

Dear Rooters,

I need to perform some numerical calculations including PolyGamma function of order n. It is defined as the (n+1)st derivative of the logarithm of the gamma function: d^n LnGamma(z)/dz^n

(more about the function is here:
http://mathworld.wolfram.com/PolygammaFunction.html)

I didn't find the appropriate function in TMath, except TMath::LnGamma(z), but the problem is how can I differentiate n times?

I'd be very grateful for any help.

---

OS Windows XP, Root 5.14.00

-- 
Sincerely,

                      Andrey K.

   *************************************************************


   * Andrey Kormilitsin    *                                   *

   *                       *                                   *

   * Department  of        *                                   *

   * Particle Physics      *                                   *

   * School of Physics     *  Tel: ++ 972- 3 - 640 7954 (o)    *

   * Tel Aviv University   *                                   *

   * Ramat Aviv,Tel Aviv   *  E-mail: andreyk1_at_post.tau.ac.il  *

   * 69978, ISRAEL         *                                   *

   *                       *                                   *

   *************************************************************


----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.

Received on Wed Apr 11 2007 - 15:03:46 CEST