Re: ReplaceAll doesn't replace

*To*: mathgroup at smc.vnet.net*Subject*: [mg32561] Re: [mg32550] ReplaceAll doesn't replace*From*: Ken Levasseur <Kenneth_Levasseur at uml.edu>*Date*: Sun, 27 Jan 2002 03:28:48 -0500 (EST)*References*: <200201260908.EAA14512@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Ken: The reason nothing is happening to x in (#^2 & /@ x) is that you're using Map, which will map the function #^2& over the arguments of x, of which there are none. You probably want (#^2 & @ x); or if you really want to use Map: Map[#1^2 & , x, {0}], where the {0} specifies that the function is applied to level 0, not level 1. Ken Levasseur Math. Sci. UMass Lowell Ken Morgan wrote: > I understand how the following will replace x with the list > > #^2 & /@ (x /. x -> {a, b, c}) > > to generate > > {a^2, b^2, c^2} > > But, why isn't x replaced at the beginning of the evaluation in the > following > > (#^2 & /@ x) /. x -> {a, b, c} > > since it generates > > {a, b, c} > > What I really want to know is: What is it about the Function function that > doesn't allow ReplaceAll to "replace all" at the beginning of an evaluation? > > Thanks, > Ken Morgan > kmorga51 at calvin.edu

**References**:**ReplaceAll doesn't replace***From:*"Ken Morgan" <kmorga51@calvin.edu>