Re: Derivative
- To: mathgroup at smc.vnet.net
- Subject: [mg95872] Re: Derivative
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Thu, 29 Jan 2009 05:52:08 -0500 (EST)
- Organization: The Open University, Milton Keynes, UK
- References: <glpgeg$lin$1@smc.vnet.net>
In article <glpgeg$lin$1 at smc.vnet.net>, "Cetin Haftaoglu" <cetin.haftaoglu at bam.de> wrote: > I have a function > > Norton[arg_,exp_,nenner_]:= MCB[arg / nenner]^exp > > I want to define my own deviation of the function Norton, > D[Norton[arg,exp,nen],y[1]]:=dNdx[arg,exp,nen] > > arg depends on y[1]. > > I have tried it with > > Derivative[1,0,0][Norton][arg_,n_,k_]:=dNdx[arg,n,k] > > But I get an error. Assuming I have correctly understood what you want, define an upvalue should do it. For instance, In[1]:= Norton /: D[Norton[arg_, n_, k_], arg] := dNdx[arg, n, k] In[2]:= UpValues[Norton] Out[2]= {HoldPattern[\!\( \*SubscriptBox[\(?\), \(arg\)]\(Norton[arg_, n_, k_]\)\)] :> dNdx[arg, n, k]} In[3]:= Norton[arg_, exp_, nenner_] := MCB[arg/nenner]^exp In[4]:= ?Norton Global`Norton Norton/:\!\( \*SubscriptBox[\(?\), \(arg\)]\(Norton[arg_, n_, k_]\)\):=dNdx[arg,n,k] Norton[arg_,exp_,nenner_]:=MCB[arg/nenner]^exp Regards, --Jean-Marc