Re: Define a function
- To: mathgroup at smc.vnet.net
- Subject: [mg34582] Re: [mg34556] Define a function
- From: BobHanlon at aol.com
- Date: Wed, 29 May 2002 02:44:29 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
In a message dated 5/27/02 2:19:21 AM, popp.michael at gmx.at writes:
>I want to define a function in Mathematica. But just f[x_]:=... does not
>work, because I have to define different functions for different ranges
>of
>the variable x.
>For example:
>
>x < 10: f(x) = 0
>10 < x < 20: f(x) = x
>20 < x: f(x) = x/2
>
>How to do this?
>
Clear[f];
f[x_ /; x<10] = 0;
f[x_ /; 10<=x<20] := x;
f[x_ /; 20<=x] := x/2;
Plot[f[x], {x,5,40}];
Clear[f];
f[x_] := x*(UnitStep[x-10]-UnitStep[x-20]/2);
Plot[f[x], {x,5,40}];
Bob Hanlon
Chantilly, VA USA