Re: Piecewise functions

*To*: mathgroup at smc.vnet.net*Subject*: [mg51590] Re: [mg51553] Piecewise functions*From*: Tomas Garza <tgarza01 at prodigy.net.mx>*Date*: Sat, 23 Oct 2004 00:23:28 -0400 (EDT)*References*: <200410220222.WAA07319@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Use "/;" (Condition) in the definition of y (and, of course, use the correct Mathematica syntax). In[1]:= y[x_] := x /; x > 3; y[x_] := -x /; -1 < x < 3; y[x_] := 1 /; x < -1; In[2]:= Plot[y[x], {x, -2, 5}]; Tomas Garza Mexico City ----- Original Message ----- From: "Luca" <luca at nospam.it> To: mathgroup at smc.vnet.net Subject: [mg51590] [mg51553] Piecewise functions > Hi all. I'm studying for the exam of signals and systems and I was > trying to plot some kind of functions I transformed for exercise. So, I > need to plot piecewise functions like: > > y(x) = x if x > 3 > y(x) = -x if -1 < x < 3 > y(x) = 1 else > > (should have been a system). > I found out in the guide the chapter about this, and I learned that it > is possible with the function UnitStep, which I know. Anyway, I found > it difficult to determine the equation of the function using this > method. Is it possible to do it simply writing everything like I did > before, more or less? i.e. without having to determine the equation > with the UnitStep function. > Hope I've been clear enought. Many thanks. > > Luca > >

**References**:**Piecewise functions***From:*Luca <luca@nospam.it>