Talk:Periodic scale: Difference between revisions

Inthar (talk | contribs)
Inthar (talk | contribs)
 
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== The step form of a scale ==
== The step form of a scale ==
I'd like the page to mention the two ways of writing a periodic scale as a function:
I'd like the page to mention the two most standard ways of writing a periodic scale as a function:
# The ''cumulative form'' (the formalization in the article), a monotone increasing function <math>S: \mathbb{Z}\to \mathbb{R}</math> such that ''S''(0) = 0 (unison) and ''S''(''k'' len(''S'')) = ''kE'' where ''E'' is the equave.
# The ''cumulative form'' (the formalization in the article), a monotone increasing function <math>S: \mathbb{Z}\to \mathbb{R}</math> such that ''S''(0) = 0 (unison) and ''S''(''k'' + len(''S'')) = ''S''(''k'') + ''E'' where ''E'' is the equave.
# The ''step form'', the sequence of steps in the scale, related to the above via Δ''S''(''k'') = ''S''(''k'' + 1) &minus; ''S''(''k''), which is nonnegative and periodic in the usual math sense.
# The ''step form'', the sequence of steps in the scale, related to the above via Δ''S''(''k'') = ''S''(''k'' + 1) &minus; ''S''(''k''), which is nonnegative and periodic in the usual math sense.
The latter form is implicitly used when regarding scales as scale words.
The latter form is implicit when regarding scales as scale words.


We can also mention scales considered more abstractly, <math>S: \mathbb{Z}\to A</math> where ''A'' is any torsion-free abelian group such as <math>\mathbb{R}</math> (log-frequency interval space), a free abelian group on steps, or a JI subgroup.
We could also mention scales considered more abstractly, <math>S: \mathbb{Z}\to A</math> where ''A'' is any torsion-free abelian group such as <math>\mathbb{R}</math> (log-frequency interval space), a free abelian group on steps, or a JI subgroup.
[[User:Inthar|Inthar]] ([[User talk:Inthar|talk]]) 16:33, 8 February 2024 (UTC)
[[User:Inthar|Inthar]] ([[User talk:Inthar|talk]]) 16:33, 8 February 2024 (UTC)
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