Re: What is f[1]? Advanced question

*To*: mathgroup at smc.vnet.net*Subject*: [mg131327] Re: What is f[1]? Advanced question*From*: "Louis Talman" <talmanl at gmail.com>*Date*: Fri, 28 Jun 2013 04:15:13 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-outx@smc.vnet.net*Delivered-to*: mathgroup-newsendx@smc.vnet.net*References*: <20130626011408.DC7E86A2B@smc.vnet.net>

On Tue, 25 Jun 2013 19:14:08 -0600, amannucci <Anthony.J.Mannucci at jpl.nasa.gov> wrote: > I have found a Mathematica program with the following construct: > x[1]=0.1 > x[2]=0.2 > x[3]=0.3 > or > Do[x[i]=i/10.,{i,1,3}] > x is not a function. It is not a list. What is it? If I query x thus: > ?x x most certainly *is* a function. Its a function whose domain contains just the three numbers 1, 2, and 3. And it is *not* an array. Mathematica has lists, which it uses as arrays on occasion. An array, y, is indexed with double brackets: a[[1]], a[[2]], etc. --Louis A. Talman Department of Mathematical and Computer Sciences Metropolitan State University of Denver <http://rowdy.msudenver.edu/~talmanl>

**References**:**What is f[1]? Advanced question***From:*amannucci <Anthony.J.Mannucci@jpl.nasa.gov>