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[DPRG] which vector? what vector?
Subject: [DPRG] which vector? what vector?
From: Dean Hall
dwhall256 at gmail.com
Date: Sun Apr 27 18:46:24 CDT 2008
"Vector (spatial), an object defined by both magnitude and direction;
in contrast to a scalar, an object with magnitude only."
-- http://en.wikipedia.org/wiki/Vector_%28spatial%29
Notice that it says direction. That can be any unit of direction and
any number of dimensions. In your case you said "distance + angle",
so "distance" is the magnitude and "angle" is the direction.
However if I were to nit-pick, I would say there is something wrong
with your sentence. A Cartesian coordinate system means a
rectangular coordinate system (usually X and Y for 2 dimensions). So
a Cartesian vector [3, 4] would be a vector that goes +3 in the X
direction and +4 in the Y direction and whose magnitude is 5 and
direction is atan(4/3) or roughly 53.1 degrees counter-clockwise from
the +X axis.
When you tell me you have a vector given as distance + angle. I
would say you have a vector in polar coordinates; whose variables are
usually given as [r, theta]. r is the distance, theta is the angle.
One can convert Cartesian to Polar systems and back. Thus the
Cartesian vector [3, 4] is equivalent to the Polar vector [5, atan
(4/3)].
!!Dean
On Apr 27, 2008, at 18:02 , Dale Wheat wrote:
> Math folk,
>
> What do you call a distance + angle, specifically on a Cartesean
> plane? Is it some kind of vector? I do so dislike sounding un-
> edumacated. You'd think Google would tell me, but no.... In
> truth, it tells me too much and my currently limited math skills
> fail me.
>
> I like using the correct terms to describe things, especially in my
> code. Any clarification is appreciated.
>
>
> Thanks,
>
> Dale Wheat
>
> (972) 486-1317
> (877) DALE WHEAT
> http://dalewheat.com
> _______________________________________________
> DPRGlist mailing list
> DPRGlist at dprg.org
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