Generator gronut/Mathematics

From Xenharmonic Reference
This is a technical or mathematical page. While the subject may be of some relevance to music, the page treats the subject in technical language.

(Under construction)

Definition

Let m>1 and n>m,gcd⁡(n,m)=1 be integer edos and fix a generator g,2≤g≤m−2 with gcd⁡(g,m)=1. Let h be the modular inverse of g modulo m.

Consider the "cylinder" C=ℤ/m×[0,1) with coordinates (x,y) = (along "longitude", along "meridian"). Follow the following procedure:

  1. Glue copies of the real interval ("line segment") [0,1) end to end, making a (continuous) circle of circumference m. For every copy of [0,1) the next copy is the one that is h steps away along the longitude.
  2. Take n equally spaced points on said circle. For sake of canonicality one of the n points is taken to be a "glue point".
  3. Unglue the line segments and put them back at their original positions.

The resulting embedding of ℤ/n into C is called the (n,g∖m)-gronut.