Re: Re: Creating a set from two other sets
- To: mathgroup at smc.vnet.net
- Subject: [mg84779] Re: [mg84774] Re: Creating a set from two other sets
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Mon, 14 Jan 2008 03:45:49 -0500 (EST)
- Reply-to: hanlonr at cox.net
Clear[f];
f[x_ /; 3 <= x <= 10] := x^2;
Plot[f[x], {x, 0, 13},
PlotStyle -> {{Red, Thick}},
Frame -> True, Axes -> False]
Clear[f];
f[x_] := x^2 /; 3 <= x <= 10;
Plot[f[x], {x, 0, 13},
PlotStyle -> {{Red, Thick}},
Frame -> True, Axes -> False]
Clear[f];
f[x_] := Piecewise[{{x^2, 3 <= x <= 10}}];
Plot[f[x], {x, 0, 13},
PlotStyle -> {{Red, Thick}},
Frame -> True, Axes -> False]
In the first two cases, the function is undefined outside of the range 3<=x<=10. In the last case, it defaults to 0 outside of the specified range.
Bob Hanlon
---- Arne Hallam <ahallam at iastate.edu> wrote:
> This is great. Thank you.
>
> I did not know how to use table in picking from a set. I had defined
> the sets a and b so I just did the following.
>
> a={0, 1, 2, 3, 4};
> b={-1, 1, 2, 3};
> SA=Table[x/y,{x,a},{y,b}]
>
>
> Thanks.
>
> Any easy way to create a set with an infinite number of members as in
> 3<=x<=10?
>
> Bob Hanlon wrote:
> > In v6 you can also do this directly with Table
> >
> > Outer[#1/#2 &, {0, 1, 2, 3, 4}, {-1, 1, 2, 3}] ==
> > Table[a/b, {a, {0, 1, 2, 3, 4}}, {b, {-1, 1, 2, 3}}]
> >
> > True
> >
> >
> > Bob Hanlon
> >
> > ---- Steve Luttrell <steve at _removemefirst_luttrell.org.uk> wrote:
> >> In[1]:= Outer[#1/#2&,{0,1,2,3,4},{-1,1,2,3}]
> >> Out[1]= {{0,0,0,0},{-1,1,1/2,1/3},{-2,2,1,2/3},{-3,3,3/2,1},{-4,4,2,4/3}}
> >>
> >> Stephen Luttrell
> >> West Malvern, UK
> >>
> >> <ahallam at iastate.edu> wrote in message news:fmcqap$ga0$1 at smc.vnet.net...
> >>> So I would like to create a set AB which consists of all ratios a/b
> >>> where a is an element of {0,1,2,3,4} and b is an element of
> >>> {-1,1,2,3}. Table does not seem to let me use elements of a set as
> >>> compared to sequential lists.
> >>>
> >>> Any ideas?
> >>>
> >>>
> >
>
> --
> with all thy getting get understanding---Proverbs 4:7.
>
> The gentle art of being gentle---of kindness and forgiveness,
> sensitivity and thoughtfulness and generosity and humility and good
> old-fashioned love---have gone out of fashion. Ironically, everyone is
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> caring place to live, to be, to learn, and to flourish---N.T. Wright.
>
> In the wildness of speculation it has been suggested (of course more in
> jest than in earnest),that Europe ought to grow its corn in America, and
> devote itself solely to manufactures and commerce, as the best sort of
> division of the labour of the globe---Thomas Malthus, An Essay on the
> Principle of Population Book III, Chapter XII.
>
> Arne Hallam
> Department of Economics
> 266 Heady Hall
> Iowa State University
> Ames, IA 50011
>
> ahallam at iastate.edu
> Work: 515-294-5861
> FAX: 515-294-0221
> Home: 515-292-8739