Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2003
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2003

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

Search the Archive

Re: Re: Derivative of a funtion evaluated at a point in 3D

  • To: mathgroup at smc.vnet.net
  • Subject: [mg44474] Re: [mg44468] Re: Derivative of a funtion evaluated at a point in 3D
  • From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
  • Date: Wed, 12 Nov 2003 08:01:25 -0500 (EST)
  • References: <boign7$oj1$1@smc.vnet.net> <200311110055.TAA25212@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

I guess nobody answered you because everyone expected someone else to 
do so. The answer is pretty trivial, in Mathematica you don't define a 
function by:

>> F[p1,p2,p3,p4] = stuff

but by

F[p1_,p2_,p3_,p4_] = stuff

You then use

D[F[p1,p2,p3,p4],p1] to get the first derivative with respect to p1, 
D[F[p1,p2,p3,p4],{p1,2}] to get the second and so on. I am afraid there 
are no shortcuts in Mathematica and you just have to learn the basics 
yourself.

Andrzej Kozlowski

On 11 Nov 2003, at 09:55, mroc wrote:

> mroc_1000 at hotmail.com (mroc) wrote in message 
> news:<boign7$oj1$1 at smc.vnet.net>...
>> Hello, I am totally new to Mathematica and trying to program a simple
>> FEM-type problem. I am trying to take the partial derivative
>> (symbolically) of an expression that is a function of four points in
>> 3D. All I can think of to do is F[p1,p2,p3,p4] = stuff then
>> D[F,p1,p2,p3,p4] . But I keep getting a zero expression as a result.
>> (where stuff is a nasty combination of these points) Any thoughts?
>
> Anyone? What am I missing? Is this question too easy or too hard?
>
>
>


  • Prev by Date: Re: Derivative of a funtion evaluated at a point in 3D
  • Next by Date: Re: Unevaluated
  • Previous by thread: Re: Derivative of a funtion evaluated at a point in 3D
  • Next by thread: Re: Re: Derivative of a funtion evaluated at a point in 3D