Re: What is f[1]? Advanced question

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• 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)
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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>

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