Re: Piecewise functions

*To*: mathgroup at smc.vnet.net*Subject*: [mg23498] Re: [mg23119] Piecewise functions*From*: "Flumpy" <Flumpy at microsoft.com>*Date*: Sun, 14 May 2000 17:00:01 -0400 (EDT)*Organization*: MindSpring Enterprises*References*: <8e0m31$f0p@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

I have a pair of mittens. Can you say, "Kitty" ? <Matt.Johnson at autolivasp.com> wrote in message news:8e0m31$f0p at smc.vnet.net... > > > An- > > You can define a piecewise function by use of UnitStep[x]... > > Suppose I have 3 functions: > > x^2 for x<=0 > x for 0<=x<=10 > -x+20 for x>=10 > > Then they can be defined with UnitStep[]: > > fun1[x_] := x^2*UnitStep[-x]; > fun2[x_] := x*(UnitStep[x] - UnitStep[x - 10]); > fun3[x_] := (-x+20)*UnitStep[x - 10]; > > Then, we can combine these into one function and plot to check it: > > fun[x_] := fun1[x] + fun2[x] + fun3[x]; > Plot[fun[x], {x, \(-10\), 20}]; > > The UnitStep function also allows integration: > > In[31]:= > Integrate[fun[x], x] > > Out[31]= > x^3/3 + 20(-10 + x) UnitStep[-10 + x] - > 2(-50 + x^2/2) UnitStep[-10 + x] + > 1/2 x^2 UnitStep[x] - 1/3 x^3 UnitStep[x] > > -matt > > > > > > An Le <an_le at brown.edu> on 04/19/2000 12:30:49 AM > > Subject: [mg23498] [mg23119] Piecewise functions > > > > > Can someone send me some notebook and package files to do piecewise > functions? I can't seem to be able to do it with mathematica. > > The only thing i get close to is using the Which[] function, but I can't > integrate with that function. > > Thanks... > > > > > > >