Re: Best practice passing expressions to functions

*To*: mathgroup at smc.vnet.net*Subject*: [mg85318] Re: Best practice passing expressions to functions*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Tue, 5 Feb 2008 19:48:18 -0500 (EST)*Organization*: Uni Leipzig*References*: <fo9gvu$t1l$1@smc.vnet.net>*Reply-to*: kuska at informatik.uni-leipzig.de

Hi, SetAttributes[defineAFunction, HoldFirst] defineAFunction[name_Symbol, expr_] := Module[{vars}, vars = Select[Cases[expr, _Symbol, Infinity], Context[#] =!= "System`" &]; SetDelayed @@ {name @@ (Pattern[#, Blank[]] & /@ vars), expr} ] and after defineAFunction[blub, Sin[Pi*x] + y*z - Log[q]] you have In[]:=blub[x, y, z, q] Out[]=x y - Log[z] + Sin[\[Pi] q] Regards Jens Remo Aschwanden wrote: > Hi > > I want to write procedures that accept expressions as parameters and be > able define functions based on these expressions, i.e. > > f[exp_]:=Module[ > "g[x_] := exp " > ] > > The code between the " " should clarify what I intend to do. Calling > f[x^2-2x+4] > should lead to the definition of a function (or pattern) > g[x_]:=x^2-2x+4; > > What's the best way to do this? How can I do this without being > dependent on the variables used in the expressions ("x")? > > Thank you. > Remo A. > >