Re: Set function

*To*: mathgroup at smc.vnet.net*Subject*: [mg64430] Re: Set function*From*: dh <dh at metrohm.ch>*Date*: Fri, 17 Feb 2006 04:11:37 -0500 (EST)*References*: <dt1c5b$1r$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi Unal, (a,b] is not a data structure available in Mathematica. You must use data structures of the Form Type[data], where Type can e.g. be List or a Type of your own choosing. Examples using Lists: ClosedSet={closed,a,b,closed}; OpenSet={open,a,b,open}; SemiCLosed={open,a,b,closed} Example using ArbitraryType[data..]: MyOpenSet= MySet[open,a,b,open] or we can put the information about closeness into the header: MyOpenSet= OpenSet[a,b] Functions can then be set up like: fun[{open,a_,b_,open}]:=.... for the first case or fun[MySet[open,a_,b_,open]]:=.. or fun[OpenSet[a_,b_]]:=... Here is an example: MySet1 = OpenSet[2, 3]; MySet2 = CloseSet[1, 10]; fun[OpenSet[a_, b_]] := 2a - b; fun[CloseSet[a_, b_]] := a - 5 b; fun[MySet1] fun[MySet2] 1 -49 Daniel Unal Ufuktepe wrote: > I am trying to do define set function as follows: > Let A=[a,b] > (closed set);or (a,b) (open set) or (a,b] or [a,b) (semi > closed sets) > f(A) is piecevise function with respect to A (closed, open > or semi closed) > > Let f(A)=2a-b if > A=[a,b] > =a-2b > if A=(a,b) > =3a-2b > if A=(a,b] > =5a-3b if > A=[a,b) > > How can I define this function? I tried "Switch" > command but because of [. ],[. ),... symboles It did not > worked. > > > Unal Ufuktepe,PhD > Izmir Institute of Technology > Department of Mathematics, > GUlbahce-Urla, Izmir 35435 > Phone:(232)-7507614 > Home:232-7571614 > Mobile phone: 5358969646 >