MathGroup Archive 1990

[Date Index] [Thread Index] [Author Index]

Search the Archive

D and Derivative - help please

  • To: mathgroup at
  • Subject: D and Derivative - help please
  • From: uunet!uthvm1.bitnet!AN123651
  • Date: Thu, 22 Mar 90 12:41:28 CST

I would appreciate some help with this from anyone who understands
Mathematica better than I. Suppose I define a function:

   f[x_,y_] := x + y + Gamma[x,y]

When I take its derivative using D, everything is fine.


   1 + Gamma     [x, y]

Derivative, on the other hand, can't get as far.



Now, suppose I define my own value for the derivative of the
Gamma function.

   Derivative[1,0][Gamma] = Plus

D understands this perfectly, but Derivative not at all.


   1 + x + y




   f     [x, y]

What's the difference here? How can I get Derivative to use my

Thanks for any help.

                               E. Neely Atkinson
                               AN123651 at UTHVM1.BITNET
                               neely at

  • Prev by Date: N
  • Next by Date: Re: N
  • Previous by thread: Re: N
  • Next by thread: Mathematica speedup technique