Re: IntervalComplement

*To*: mathgroup at smc.vnet.net*Subject*: [mg70324] Re: IntervalComplement*From*: Bill Rowe <readnewsciv at sbcglobal.net>*Date*: Fri, 13 Oct 2006 01:30:07 -0400 (EDT)

On 10/12/06 at 5:38 AM, chris at chiasson.name (Chris Chiasson) wrote: >Has anyone implemented this function before? I need something that >can do this. Hmm... One way to interpret what you have asked for is a function that returns a list of intervals containing all points not contained by the intervals returned by IntervalUnion. Using that as the function definition then IntervalComplement could be written as: In[7]:= IntervalComplement[int___Interval] := ({Interval[{-Infinity, Min[#1]}], Interval[{Max[#1], Infinity}]} & )[ Flatten[Apply[List, {int}, {1}]]] testing: In[9]:= int1=Interval[{1,10}]; int2=Interval[{8,12}]; int3=Interval[{20,30}]; IntervalComplement[int1,int2,int3] Out[12]= {Interval[{-Infinity, 1}], Interval[{30, Infinity}]} seems to work correctly. But this result doesn't seem useful to me which leads me to believe I don't really understand what you are asking for. -- To reply via email subtract one hundred and four

**Follow-Ups**:**Re: Re: IntervalComplement***From:*"Chris Chiasson" <chris@chiasson.name>