[WCA Regulations 2014] Clock Notation

[TMOY]

Not at all. And as TMOY said above: "It's even a trivial problem since both notations use the same basis, only in a different order." (I haven't checked it, but I trust him )

Well, you shouldn't, because when comparing the different notations in your picture I just realised that I was wrong . Look at the four "1 pin different from the other 3" generators: with the old notation, you have to turn one of the three wheels corresponding to the three pins in the same state; in the new one, you have to turn the fourth one.

But the problem is still not very difficult, you only have to apply the appropriate transformation matrix to translate a given scramble from one notation to another.

 

[kinch2002]

I definitely like the idea of 2 notations. One for noobs, one for people who have actually scrambled clocks before.

For the latter, we don't need the UUdd stuff. Just concise notation (i.e. (-2,3) (0,4) etc) would be appropriate because if you've scrambled 100 clocks, you now know what the pin order is and it's pointless to write it down.

This will never result in both scrambles being applied because anyone who doesn't understand what's going on won't be able to read the concise notation anyway and will have to ask what it's there for, and then be told that they can ignore it.

 

[Mollerz]

With the old notation, new clock solvers and inexperienced scramblers scrambled slowly, and fast clock solvers scrambled fast. With the new notation, new clock solvers and inexperienced scramblers scramble slowly, and fast clock solvers still scramble slowly.

If concise notation is implemented (Alongside the current notation, or even on its own), then it'll increase scrambling accuracy and also double the speed at which fast solvers scramble. I've done an Ao12 for scrambling each type of notation, for concise I get on average around 9-10, for WCA I get anywhere from 18-22.

 

[AvGalen]

Poll?
1) Just get rid of Clock
2) Only use New
3) Only use Old
4) 2 scrambles: New and Old
5) 2 scrambles: New and Old-Short-Form
6) 2 scrambles: Old and Old-Short-Form
7) 3 scrambles: New, Old and Old-Short-Form

I would vote for 5: "2 scrambles: Beginner=New, Expert is Old-Short-Form

New pin-notation confuses me
Old pin-position slows me down
I would prefer old-short-form only for me personally, but I understand beginners might prefer New

 

[Dene]

If we're voting, I pick 1

 

[qqwref]

Sadly I can't read the new short-form notation and I hate the new notation :|

Honestly, I think we ought to just get rid of the new notation altogether. It's unnatural, uses capital letters for things that aren't even turns, and uses very similar "moves" to mean very different things. It wouldn't be very hard to think of a notation that is better but still different from the old notation. The old notation was fine (that is, I prefer AvG's option 3). If we really need to have two notations, we can use AvG's option 6.

 

[Stefan]

I've done maybe 20-30 scrambles using the "UUdd..." notation at worlds, I've already forgotten the order (so concise wouldn't work for me), and now that I tried the new notation, I instantly like the new notation ("UR1+...") much better.

 

[Pedro]

I don't understand how people don't understand (bleh) the new notation.

The old one used capital and non-capital letters for things that aren't turns, so that doesn't seem to be the problem.

I had no problem adapting to the new notation, but if people prefer to have both, that's fine for me.

 

[Yuxuibbs]

Poll?

If we're voting, I'm fine with any type of Jaap notation. I don't really care for the new notation so I would vote for all of 3-7. If we can only choose 1 option, I would vote for 4.
For weekly comps and stuff, it's fairly easy for me to just ignore the letters and only look at the numbers when I scramble with something that isn't concise notation. When I'm just practicing, I use concise notation.

 

[Michael Womack]

This thread and issue would have never happened if we had stuck with the older Jaap scrambles.

 

[AvGalen]

This thread and issue would have never happened if we had stuck with the older Jaap scrambles.

or would have gotten rid of Clock
or if speedsolving would be down more often.

2 out of 3 seem like a good idea

 

[yockee]

Not that I ever get to go to competitions, since they never have them in Manchester, but I say remove clock and add Square 2.

 

[Kit Clement]

I haven't spent the time to build the change of basis matrix yet, but I did create two matrices representing the 14 basis vectors corresponding to each scramble. I have to run, but if someone else would like to input this into some program (mathematica, matlab), and do the necessary row reductions, feel free. If not, I'll do it sometime soon. I also figured it would be worth it to post this now in case anyone detected an error that I did not catch.

The matrices: http://i.imgur.com/uFNwu0s.jpg

The key is hard to decipher, so here's what I used:

Corners (corresponding to front center): UL = 1, UR = 2, DL = 3, DR = 4
Front: U = 5, L = 6, C = 7, R = 8, D = 9
Back: U = 10, L = 11, C = 12, R = 13, D = 14

All numbers are indicating the direction they would go as if you faced that side (except for corners on the back, as they had to be oriented to one side). Also, the large 0s are block matrices of all 0s of the appropriate size.

EDIT: already noticed an error, the UUUU column should be all 1s, no -1s

 

[Michael Womack]

Why would w Remove the Clock event?

 

[Kit Clement]

https://www.dropbox.com/sh/c9vhwyv4qnst9fq/2Ki5IUiPVO

Here's my progress so far on the Clock Transformation matrix - I've used Maple 16 to do the calculations on this matrix. I don't have a clock on me currently, so I cannot check it, however, I will update these documents with a scramble of my own and the output scramble to test it. For those that want to try it out, take the numbers in a current-type scramble in the order they read, place them in a vector in that order, and then perform matrix multiplication. The resulting numbers should be the scramble numbers in order for the old-type notation. It's in mod 12 form right now, so for all numbers >= 7, subtract 12 to get the typical clock scrambling number.

EDIT: New proposition that Sarah and I have discussed: what if we could just build a separate tool that would take TNoodle output and transform it into the Jaap scrambling notation? That way we don't have to change anything regulations-wise. If possible, could we have a data dump of all the numbers used in scrambling at the bottom of the TNoodle output?

EDIT 2: The matrix was done for the inverse transformation, this is fixed. Those who have maple can try editing the scramble1 variable to match any scramble of your choice, it will output the same scramble with numbers for Jaap. One example is done already in the pdf in dropbox, which you can see for yourself is the same scramble.

 

[TMOY]

I haven't checked your computations in detail, but a 14'x28 matrix, wtf ? Why isn't it just 14x14 ?

 

[Kit Clement]

I haven't checked your computations in detail, but a 14'x28 matrix, wtf ? Why isn't it just 14x14 ?

Setting up for row reduction to create the 14x14 matrix. To find such a transformation matrix, you can take the two bases and put them into one matrix, where the first 14 columns are the basis of the range, and the second 14 columns are the basis of the domain. After row reduction, you'll have a matrix containing two block matrices, one being the identity and the other being the transformation matrix. I've probably updated my PDF since you looked - it will extract this 14x14 block in the line where T is declared.

 

[AvGalen]

Why would w Remove the Clock event?

Because having Clock but not other events is pretty random. Clock is not a very interesting puzzle and the only reason we are doing it is because we have been doing it. The only reason we have been doing it is because it is an official Rubik's puzzle.

 

[Kit Clement]

Sure, I'd like to, but there's no documentation - I can't be sure how it works, what the probabilities are, what moves are possible where, and so on. I wouldn't want to make a WCA scrambler that doesn't even work properly, after all.

Bumping this as Sebastien brought up this post in a regulations discussion here: https://github.com/cubing/wca-documents/issues/60

Since the current notation acts as a "basis" for the "vector space" (technically free module over integers mod 12 as TMOY pointed out to me), each scramble (or element of the free module) has a 1:1 relationship with a vector that encodes the scramble information. Because of this, creating a random state generator for clock is as simple as generating random integers in [-5, 6] for each pin position. Each pin has probability 1/2 of being up.

 

[DrKorbin]

What I'm not sure of is how the pin position is generated: if each pin has probability 1/2 of being up, or if all possible pin states have equal probability.

That's the same thing.