Re: Please Help Eliminate My Ignorance
- To: mathgroup at smc.vnet.net
- Subject: [mg118567] Re: Please Help Eliminate My Ignorance
- From: Tomas Garza <tgarza10 at msn.com>
- Date: Tue, 3 May 2011 05:45:47 -0400 (EDT)
Mathematica finds no problem with 1. You are just defining the function test (only if you try to evaluate iyou=B4ll be in trouble, since there is no p). The problem in 2. arises because you have just Clear'ed p, and so Append[p, p[[4]]] makes no sense: there is no p. -Tomas > Date: Mon, 2 May 2011 06:52:02 -0400 > From: mmandelberg at comcast.net > Subject: [mg118542] Please Help Eliminate My Ignorance > To: mathgroup at smc.vnet.net > > Why does Mathematica like the first, but not the second? > > 1. > Clear[x, testp, p]; > test[p_] := Append[p, p[[4]]]; > > > 2. > Clear[x, testp, p]; > test[p_] := x = 1; Append[p, p[[4]]]; > > Part::partd: Part specification p[[4]] is longer than depth of object. > >> > > Append::normal: Nonatomic expression expected at position 1 in > Append[p,p[[4]]]. >> >