# Message #1447

From: Andrey <andreyastrelin@yahoo.com>

Subject: Re: [MC4D] Social dream

Date: Tue, 22 Feb 2011 18:56:39 -0000

Okay, let’s write fractions of full turn: 1/2,2/3,2/5,37/100 etc. It’s universal (in 4D puzzles) and not a big problem for programs.

So twist record will look like 15:23:2/3:8 .

To enumerate axes of the set we can select some coordinate system (that is natural for tesseract, 24-cell and duoprisms, and we can select something for 5-cell and 120-cell), get vectors of length 1 in directions of all axes, sort them in by w coordinate, then by z, by y and at last by x, and select the last (maximal) vector as 0, next as 1 and so on (for vectors greater than (0,0,0,0)). It may be difficult for human, but easy for the program.

Andrey

— In 4D_Cubing@yahoogroups.com, "Andrey" <andreyastrelin@…> wrote:

>

> I thought about usage of degrees (72, 120, 90,…) but it will not work for douprisms. Actually I want to have rational number there, but it’s more easy to write their common denominator is the head (near the set description) and show only numerators of the angle in all twists. We may write D=360 for all puzzles other than douprisms.

> Or you want to write denominators only? Then again we’ll need two records for 144-deg rotation… Not good when we can select format with one record for every twist of the cell/face/edge/vertex…

>

> Andrey

>

> >

> > But if I’m reading right, you are suggesting a 180-degree rotation on the

> > 120-cell puzzle would be angle=30 (60/2). So the nature of the puzzle does

> > seem to affect how the same twist angle is recorded. It feels like it’d be

> > nicer if the recording of angles did not have this kind of dependency.

> >

> > seeya,

> > Roice

> >

>