Re: Best syntax for derivative

*To*: mathgroup at smc.vnet.net*Subject*: [mg96418] Re: [mg96386] Best syntax for derivative*From*: Carl Woll <carlw at wolfram.com>*Date*: Fri, 13 Feb 2009 03:43:01 -0500 (EST)*References*: <200902121141.GAA08658@smc.vnet.net> <49943ED6.6070407@wolfram.com> <38178b720902120742v622b315es505bb5bd96b52c59@mail.gmail.com>

Aaron Fude wrote: > Thanks. That's cool. May I ask a follow up question? > > What if I want to have g=f^2? > > Is there a similar alternative to > > g[x_, y_, z_] := f[x, y, z]^2? > > Thanks again! The Derivative thing can work because the number of arguments it gets determines how many arguments f has. In your example this information is unavailable, so you'll need to use Slot objects to achieve the same effect: g = f[##]^2& Carl > > > > > On Thu, Feb 12, 2009 at 10:23 AM, Carl Woll <carlw at wolfram.com > <mailto:carlw at wolfram.com>> wrote: > > Aaron Fude wrote: > > Hi, > > Suppose I have a function of three variables > > f[x_, y_, z_]:=Sin[x y z] > > And I want to construct g[x, y, z] which is the partial > derivative of f > [] with respect to y. I do > > f[x_, y_, z_] := Sin[x y z] > g[x_, y_, z_] := D[f[x, temp, z], temp] /. temp -> y > > but I'm sure there is something better. Something along the > lines of > > g = Partial[f, 2] > > Many thanks in advance. > > Aaron > > > > It's: > > g = Derivative[0, 1, 0][f] > > Carl Woll > Wolfram Research > >

**References**:**Best syntax for derivative***From:*Aaron Fude <aaronfude@gmail.com>