Message #1430

From: Roice Nelson <roice3@gmail.com>
Subject: Re: [MC4D] Social dream
Date: Sun, 20 Feb 2011 12:54:49 -0600

Hi Eduard,

I can’t give you the "table of stickers" you are asking for, because it
would be huge. I can briefly describe the log file encoding though. In
Magic120Cell, all the information for a twist is encoded into a 32-bit
integer, which is what you see in the log files. There are 63 stickers per
cell, so 6 bits are required for that. 7 bits are needed to record which of
the 120 cells the sticker is on. 1 bit is used to record the twist
direction, and another for whether or not it is a view rotation. In
retrospect, I don’t like that I packed it all into an integer. It is
compact, but people want to look in the log files and understand them, and
this representation is opaque. For the MagicTile log files I did a few
weeks ago, I made it more reader friendly. Andrey has suggested we come up
with a standard format, so I’m sure some of these issues will arise when
that is discussed.

MC4D has a different encoding of twists. I didn’t check the source code
(which is available
online<http://code.google.com/p/magiccube4d/source/browse/>),
but I’m pretty sure the last digit you were asking about is a
bitmask<http://en.wikipedia.org/wiki/Bitmask>representing the
slicemask of the twist (which slices were held down while
twisting). For the 120-cell puzzle with 3 stickers-per-side, this is not an
import piece of information, which is why it wasn’t part of my twist
definition above. But for other MC4D puzzles, it is important. If you had
a 120-cell puzzle with 5 stickers per side, slicemask would need to be
included.

Here are my other thoughts on this.

• I like the competitions and think they are good motivators, so making it
  such that more could participate is a worthy and positive goal. (As an
  aside, I think it’d be cool if this could be more automated…that is, if
  the software could directly support logging solutions online without human
  intervention.)
  
• While effort could be expended on a log file transfer program, I think
  the better long term solution here would be to add the missing features to
  MC4D and retire the Magic120Cell code. Also, I think the log file
  standardization Andrey has suggested would sidestep this need, assuming the
  various implementations were updated to respect it.
  
• An "evaluator" feature could be added directly to MC4D, which would show
  the percentage completed on the puzzle. You could calculate percentage
  complete on either a sticker or piece basis. This feature request would be
  good to add to the issue
  tracker<http://code.google.com/p/magiccube4d/issues/list>,
  so that it will be ready for when someone is motivated to work on it. I do
  know it will be a difficult problem to handle generally in MC4D, due to
  even-length puzzles where there aren’t unmoving central stickers. I ran
  into this when adding this feature to MC5D. FYI, right now, the MC4D code
  just cycles through stickers on a face and checks whether they are all the
  same, and does this for each face. Once it finds one different, it knows it
  is not solved and immediately returns. So it doesn’t need to think about
  how much of the puzzle is completed.

Best,
Roice

On Sat, Feb 19, 2011 at 8:13 AM, Eduard <baumann@mcnet.ch> wrote:

>
>
> (a) Introduction
>
>
>
> The marvelaous 120-Cell in 4D.
>
>
>
> The 4D Regulars are very sympathic models of perfect democratic societies
> with perfectly equal individuals. Each has an equal number of neighbours in
> equal constellation. This number is 4 for the 5-Cell, 6 for the hypercube (8
> individuals') and 12 for the 120-Cell (120 individuals’ = society).
>
> A cluster of bees in winter has to arrange changes of roles (inner / outer
> places in the cluster). Everybody wants be in the warmer inner space. No
> such problems in 4D at least for 120 bees housed in the 120-Cell. Everybody
> is equally surrounded by 12 neighbours. Perhaps arrange the bees in 3D in a
> infinite grid to avoid social problems.
>
>
>
> Let me use the abreviations „Magic" for the program Magic120Cell and
> „Hyper" for the Hypermeaminx puzzle in MC4D.
>
>
>
> (b) Combine Magic and Hyper.
>
>
>
> I think Magic and Hyper cannot share their log files.
>
> Complementarity: Magic has finding help and no macro, Hyper has no finding
> help but macro.
>
> I need both!
>
> How about a *transfer* program?
>
> Roice: can you give me a table with the two corresponding labelings of
> stickers in Magic and Hyper? I need also to know the signification of the
> last digit of the numbers in Magic log file (2 clockwise and 4 anticlockwise
> for faces, what is 6 and 8?).
>
>
>
> (c) Partial HOF
>
>
>
> The HOF for the 120-Cell has only two entries until now. Noel Chalmers and
> Matt Galla (great performer). In order to achive more participants (about
> 400 as in the Al Zimmerman contests) I propose to install HOF for partial
> results.
>
> For this I need an *evaluator*, a program which calculates the percentage
> of cubies in place and well oriented from the log file. The code must
> already existe for the checking and emitting "Congratulations" in MC4D.
>
> With this evaluator a ranking list is possible as in the Al Zimmerman
> contests (take best results of each participant).
>
> This can be a good motivation to get in touch with the 120-Cell and live a
> moment in the world of this 120 individuals (dodecahedra).
>
>
>
> If I get the evaluator and the incoming log files
>
> I propose to do the managing this of partial HOF in superliminal.com/wiki(in protected pages).
>
>
>
> Doing only the 2 colored faces in the 120-Cell is already demanding because
> you have to get a good feeling of the neighbourhoods and soon to use
> commutators to avoid the disturbing of already placed cubies.
>
>
>
> If this partial HOF is working I propose to do promotion in (1) Roice’s
> description of Magic120Cell, (2) Roice’s description of MC4D, (3)
> Superliminal.com/wiki and (4) in the "4D cubing" forum.
>
>
> What do you think all?
>
>