RE: problems with the definition of a function

*To*: mathgroup at smc.vnet.net*Subject*: [mg36657] RE: [mg36651] problems with the definition of a function*From*: "David Park" <djmp at earthlink.net>*Date*: Wed, 18 Sep 2002 02:09:34 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Fabio, f[x_ /; IntegerQ[Rationalize[x/(2Pi)]], y] := g[x] f[x_, y_] := h[x, y] f[# Pi, y] & /@ Range[10] {h[Pi, y], g[2*Pi], h[3*Pi, y], g[4*Pi], h[5*Pi, y], g[6*Pi], h[7*Pi, y], g[8*Pi], h[9*Pi, y], g[10*Pi]} f[2.0Pi, y] g[6.28319] f[3.5, y] h[3.5, y] f[4.01Pi, 5] h[12.5978, 5] You can use a second argument in Rationalize to control how small a rationalization error is allowed and there is always the question about what domain around 2nPi you want to include in the first definition. David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: fabio bagarello [mailto:bagarell at unipa.it] To: mathgroup at smc.vnet.net Hi there!! I have quite an easy and annoying problem with mathematica: I need to define a function f(x,y) which takes some values for x=0,2pi,4pi (indepently of y) and has a different expression for all the other values of y. This is easily done for one-dimensional functions but I am in serious troubles for my two-dimensional problem: any suggestion? Thanks a lot, Fabio