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Cell designation

 
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Marty R.



Joined: 12 Feb 2006
Posts: 5159
Location: Rochester, NY, USA

PostPosted: Fri Oct 03, 2008 5:00 am    Post subject: Cell designation Reply with quote

A question for you veteran players. I notice when I do the puzzles from sudoku.org.uk that the grid's rows are labeled A thru J and the columns 1 thru 9. I've also seen it on a couple of other sites. Thus, cells would be designated, for example, d5 and j8 rather than r4c5 and r9c8.

This alphanumeric designation seems easier and I wonder why it isn't in general use.
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nataraj



Joined: 03 Aug 2007
Posts: 1029
Location: Vienna, Austria

PostPosted: Fri Oct 03, 2008 5:51 am    Post subject: Reply with quote

It is probably more a matter of habit than anything else, but I'll try and give a few arguments in favor of the rxcy notation:

Numbers are well suited to give positions/coordinates, letters serve well to give a sort order (in statistical terms: interval scale vs. ordinal scale).


There is a lot of symmetry in the sudoku grid. I see no reason why one dimension should be any different from the other. Arbitrarily mixing two systems makes things harder, not easier, for me.

... Just my b cents (was that a,b,c... now or 1,2,3.. ? can't remember)

I am curious to find out what might be said in favor of the A4, F2 ... notation. Easier. Hm. How, exactly?
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keith



Joined: 19 Sep 2005
Posts: 3165
Location: near Detroit, Michigan, USA

PostPosted: Fri Oct 03, 2008 10:40 am    Post subject: Reply with quote

How do they describe blocks / boxes?

Keith
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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Fri Oct 03, 2008 3:12 pm    Post subject: Re: Cell designation Reply with quote

Marty R. wrote:
... rows are labeled A thru J and the columns 1 thru 9.

Lack of consistency among its advocates Exclamation

I've seen puzzles with rows A..K w/o I being used. I've also seen puzzles where the rows are labeled 1..9 and the columns are labeled A..J. I recall running into a puzzle where the rows were labeled in descending order as we think of them. (I don't remember if letters or number were used for the rows.)
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Marty R.



Joined: 12 Feb 2006
Posts: 5159
Location: Rochester, NY, USA

PostPosted: Fri Oct 03, 2008 3:48 pm    Post subject: Reply with quote

I don't know how boxes are designated.

I just thought that using a two-character designation is easier than a four-character. However, it seems the two-character is impractical, given what daj pointed out about the inconsistencies that he has seen.

Thanks for the responses.
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nataraj



Joined: 03 Aug 2007
Posts: 1029
Location: Vienna, Austria

PostPosted: Fri Oct 03, 2008 4:07 pm    Post subject: Reply with quote

I would call the boxes:
☿♀ ⊕ ♂ ♃ ♄ ♅ ♆ ♇ (pronounced Mercury, Venus, Earth, ...., Pluto)
"An xy-wing involving row C and box ♄...". Maybe the solar system was intelligently designed for the explicit purpose of numbering sudoku boxes?

A different scheme would be: Talc, Gypsum, ..., Corundum

Seriously, (and I was thinking about the boxes numbering problem, too):

does anyone know of a possible third system for designating ordinal scales
(or "number"ing in the broader sense) ? It seems that all there is are numbers (in different languages) and just more alphabets (Greek, Hebrew, ...).

All those thousands of years, and man came up with only two measly scales for counting (and one of them limited to a few dozen possibilities)?

In that case, numeric coordinates for the cells should be good enough Very Happy
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daj95376



Joined: 23 Aug 2008
Posts: 3855

PostPosted: Fri Oct 03, 2008 10:09 pm    Post subject: Reply with quote

nataraj wrote:
does anyone know of a possible third system for designating ordinal scales ...

Seems to me that only the first 9/10 letters of the alphabet have been used. So, boxes ...

Code:
L M N P S T U V W

1 2 3 4 5 6 7 8 9

Now, all you need to do is standardize on how everything is labelled.
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Asellus



Joined: 05 Jun 2007
Posts: 865
Location: Sonoma County, CA, USA

PostPosted: Fri Oct 03, 2008 10:53 pm    Post subject: Reply with quote

nataraj wrote:
Maybe the solar system was intelligently designed for the explicit purpose of numbering sudoku boxes?

Funny you should mention that...

A clever programmer at our observatory created a solar system sudoku program a while back that uses little images of the planets instead of digits. It has other solar system related info and stuff and is sorta fun. (The sudoku puzzle engine is not that sophisticated and the puzzles are mostly easy.) He had some beta versions. I don't know if he ever produced a "released" version. I know that it is not available at our website, which was the original idea. I'll have to investigate.
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George Woods



Joined: 28 Mar 2006
Posts: 232
Location: Dorset UK

PostPosted: Sun Oct 19, 2008 10:52 pm    Post subject: Reply with quote

nataraj wrote:
It is probably more a matter of habit than anything else, but I'll try and give a few arguments in favor of the rxcy notation:

Numbers are well suited to give positions/coordinates, letters serve well to give a sort order (in statistical terms: interval scale vs. ordinal scale).


There is a lot of symmetry in the sudoku grid. I see no reason why one dimension should be any different from the other. Arbitrarily mixing two systems makes things harder, not easier, for me.

... Just my b cents (was that a,b,c... now or 1,2,3.. ? can't remember)

I am curious to find out what might be said in favor of the A4, F2 ... notation. Easier. Hm. How, exactly?



I use, and have used ever since I started, letters to describe both boxes and cells. To define a cell totally I would formally use a foramt such as Ea, although in practice ea works just as well (E is the Eth box ie box 5, and a is the ath cell ie cell 1 in box5

So numbers relate only to "solutions" and g5 would mean the 5 in box g (i.e. box 7) is solved and inserted. I always record every move in a 'serious' suduko. This way if I make a mistake I can start agin, and retread the original path - at least to the point of the mistake - easily.

I use more than just this eg h23 would imply a naked pair 23 in box H and h22 a "locked 2"

I also use an underline to show only one candidate (i.e.every other number can be seen by the cell), and a single overstrike to show that it is derived from row analysis, and a double overstrike to show column.

I seldom find the need identify the precise cell eg ab6 (ie put a 6 in row 1 col 2).

I commend this sytem to you - I know things have gone too far for it to be adopted generally!
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