Re: Is there any efficient easy way to compare two lists with the same length with Mathematica?

*To*: mathgroup at smc.vnet.net*Subject*: [mg124387] Re: Is there any efficient easy way to compare two lists with the same length with Mathematica?*From*: James Stein <mathgroup at stein.org>*Date*: Wed, 18 Jan 2012 05:58:07 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

I learned something from the answer(s) on this thread, leading to a question of my own: Why do 'Equal' and 'SameQ' respond differently from 'Greater' and 'Less' ? e.g.: a = {1, 2, 3}; b = {3, 2, 1}; Thread[a < b] Thread[a == b] Thread[a === b] Thread[b < a] On Tue, Jan 17, 2012 at 4:01 AM, Bill Rowe <readnews at sbcglobal.net> wrote: > On 1/17/12 at 3:34 AM, aoirex at gmail.com (Rex) wrote: > > >Given two lists `A={a1,a2,a3,...an}` and `B={b1,b2,b3,...bn}`, I > >would say `A>=B` if and only if all `ai>=bi`. > > >There is a built-in logical comparison of two lists, `A==B`, but no > >`A>B`. Do we need to compare each element like this > > >And@@Table[A[[i]]>=B[[i]],{i,n}] > > I think you do need to do an element by element comparison. But > you don't need to specifically select each element using Part as > you are doing. That is: > > In[13]:= {a, b} = RandomInteger[100, {2, 5}]; > And @@ Thread[a > b] > > Out[14]= False > > In[15]:= c = RandomInteger[{150, 200}, 5]; > And @@ Thread[c > a] > > Out[16]= True > > >