[Date Index] [Thread Index] [Author Index]

Re: vector/matrix indexed from zero

• To: mathgroup at smc.vnet.net
• Subject: [mg114692] Re: vector/matrix indexed from zero
• From: Norbert Marxer <marxer at mec.li>
• Date: Mon, 13 Dec 2010 03:52:17 -0500 (EST)
• References: <ie297c$mrj$1@smc.vnet.net>

On 12 Dez., 11:47, "Vasyl&#39;" <vvavryc... at gmail.com> wrote:
> How to create vector in Mathematica index of which will start from
> zero.
>
> Now for x = {0, 1}, x[[1]] gives 0 and x[[2]] gives 1.
>
> I want x[[0]] = 0, x[[1]] = 1.

Hello

I would use OverVector to define a vector and Subscript to extract a
coordinate of a vector.
With the definition Subscript[x_List, n_] := x[[n + 1]] you can shift
the index of your first coordinate.

E.g. in InputForm

Subscript[x_List, n_] := x[[n + 1]]
OverVector[a] = {1, 3}; OverVector[b] = {2, 8};
{Subscript[OverVector[a], 0], Subscript[{3, 4}, 0],
 Subscript[OverVector[c], 0]}
OverVector[a] . OverVector[b]
OverVector[a] . OverVector[c]

If you take the above input and transform it into StandardForm
everything looks really nice and the
functions Dot, Cross etc work with your (Over)Vectors.

Best regards
Norbert Marxer

• Follow-Ups:
  • VectorPlot on a Circle
    • From: "Dave Snead" <dsnead6@charter.net>