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Re: Partial derivation with regards to variables in a list

• To: mathgroup at smc.vnet.net
• Subject: [mg51071] Re: Partial derivation with regards to variables in a list
• From: p-valko at tamu.edu (Peter Valko)
• Date: Sun, 3 Oct 2004 05:47:53 -0400 (EDT)
• References: <cjgimt$q6i$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

I do not know if I understood the question correctly, 
but (who knows?) this might help:

expr=f[a,b,c,d,e]
Operator[Derivative[1,0,0,1,0],expr]

You do not have to know the variables, 
but you do have to know how many of them are and
which partial derivative you need. 

Peter


Christopher grinde <christopher.grinde at hive.no> wrote in message news:<cjgimt$q6i$1 at smc.vnet.net>...
> Hello.
> 
> I need to find the partial derivative with regards to variables in a list.
> 
> The straight forward syntax would be
> D[f[a,b,c,d,e,],a,b,c,d,e]
> 
> My problem is that I don't know the variables up front of finding the
> derivative.
> 
> I've tried Apply[], but as I am quite new to Mathematica, I haven't been
> able to use Apply[] with functions with more than one argument.
> 
> Please advice.