Re: Problems with Set, SetDelayed and replacement rules...

*To*: mathgroup at smc.vnet.net*Subject*: [mg72283] Re: Problems with Set, SetDelayed and replacement rules...*From*: Johan Grönqvist <johan.gronqvist at gmail.com>*Date*: Mon, 18 Dec 2006 06:55:52 -0500 (EST)*References*: <em3a6c$7fq$1@smc.vnet.net>

Johannes skrev: > f[x_]:= g/h*x; > g[p_]= 1+p; > h[p_]=1+p^2; > params={g->g[p],h->h[p]}; > [...] > f3[x_, p_] := f[x] /. params; > > If I am now calculating [...], for f3[1,1] p isn't replaced by its value 1. > > Can anybody explain me the differences, especially the differences between f2 and f3? I suspected it to be exactly identical. Sorry. I cannot explain this, but it seems to work for me. f3[x_, pp_] := (f[x] /. params) //. p -> pp I thought params := ... instead of params = ... would be enough, but it seems it was not. / johan