Re: Picewise Function

*To*: mathgroup at smc.vnet.net*Subject*: [mg82090] Re: Picewise Function*From*: Girish Kulkarni <geeree at gmail.com>*Date*: Fri, 12 Oct 2007 02:48:21 -0400 (EDT)*References*: <fek98d$lae$1@smc.vnet.net>

Frank Hechtner wrote: > Now i want mathematica to tell that this function uses a specific > domain. The function should only be defined if the result of the > evaluation is <= 0.25. This sounds like you want to restrict the *range* of the function and not its domain. In that case simply discard the value that the function returns if it is greater than 0.25. OTH, if you have to restrict the *domain*, you can use Condition ( /; ). See `Condition' in Mathematica help. For example: q[x_] := x^2 /; x > 0 q[x_] := -x^2 /; x <= 0 defines a function piecewise. It evaluates to x^2 if x is positive and to -x^2 if it is not. -- Girish Kulkarni - Allahabad, India - http://girish.50webs.com