Is there a convention for the order of coordinates?

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bravado
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Joined: Thu Jun 07, 2012 11:28 am

Is there a convention for the order of coordinates?

Post by bravado »

I was wondering if there's a convention for writing coordinates?

For example, in the Bond 10 Minute Tests - 11+ - 12+ ...Test 19, Q8.

It asks you to give the two coordinates that would complete a rectangle with dimensions 3 units by 5 units . Point A is -3, 1
Point B is -3, -2

Does it matter what order points the remaining points go in the answer, or do you have to follow a convention ie if the first two are anti-clockwise, then the next anti-clockwise one on from Point B must be the first answer and the next, is the second answer?

I've tried to be as clear as I can but without a diagram, I'm at a loss
mystery
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Re: Is there a convention for the order of coordinates?

Post by mystery »

I can't think that it would matter in what order you quote the co-ordinates for a shape, so long as each co-ordinate is written in the correct way (x,y). It would be neat to quote them all in clockwise or anti-clockwise order but I don't think it could ever really matter could it?
daveg
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Re: Is there a convention for the order of coordinates?

Post by daveg »

mystery wrote:I can't think that it would matter in what order you quote the co-ordinates for a shape, so long as each co-ordinate is written in the correct way (x,y). It would be neat to quote them all in clockwise or anti-clockwise order but I don't think it could ever really matter could it?
It depends if the co-ordinates are defined as the corners of a shape (in which case the order doesn't matter) or there's an implication that you can draw from one to the next to form the shape. (0, 0), (0, 1), (1, 1), (1, 0) are the corners of a unit square, and if you draw from one to the next, and then back to where you started, you've drawn a square. (0, 0), (0, 1), (1, 0), (1, 1) are also the corners of a unit square, but if you connect the points in that order and then return to where you started, you'll have a bow-tie shape consisting of two triangles.
joseph waters
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Is there a convention for the order of coordinates?

Post by joseph waters »

Hi Bravado,

No there is no convention for the order of co-ordinates, but if the previous two were ordered anticlockwise you can assume the other two answers will be in anti-clockwise order as well, just common sense thinking...good for a person heavily involved in doing maths exam questions :P
bravado
Posts: 468
Joined: Thu Jun 07, 2012 11:28 am

Re: Is there a convention for the order of coordinates?

Post by bravado »

Thanks very much guys - so it's pretty much as I suspected 8)
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