From: Morton Goldberg <m_goldberg@...>
Date: 2007-09-13T00:05:16+09:00
Subject: Re: Filling individual cells in a grid

On Sep 12, 2007, at 4:40 AM, Joop Van den tillaart wrote:

> So the code can find al the available cell pairs...that can be useful
> for me in a next step I have to take but I still have a question...
>
> On the second thought you had you did something with delta and
> neigbours..that is what I need for now but I can't seem to get it to
> work...
>
> How can I find for example:
>
> All cells that are in a distance of 1 cell from [1, 1] (or directly
> 'touch' this cell) ?
>
> The result then has to be something like:
>
> [0,0], [1,0], [2,0], [0,1], [2,1], [0,2], [1,2], [2,2]
>
> I now your code should be able to do this but I'm not sure how... 
> (jeezz
> i feel so noobish)

I am not sure I understand what you are asking. If you want to look  
in a neighborhood around a cell that is two cells deep, shouldn't the  
deltas be given by

<code>
tmp =[]
(-2..2).each { |dx| (-2..2).each { |dy| tmp << [dx, dy]} }
DELTAS = tmp - [[0, 0]]
DELTAS # => [[-2, -2], [-2, -1], [-2, 0], [-2, 1], [-2, 2], [-1, -2],  
[-1, -1], [-1, 0], [-1, 1], [-1, 2], [0, -2], [0, -1], [0, 1], [0,  
2], [1, -2], [1, -1], [1, 0], [1, 1], [1, 2], [2, -2], [2, -1], [2,  
0], [2, 1], [2, 2]]
</code>

I mean, don't want to look left, right, over, and under?

Regards, Morton