S-expression: Difference between revisions

Godtone (talk | contribs)
Godtone (talk | contribs)
rename to avoid confusion/conflict with "smonzo"
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(Note that while a lot of these have pages, not all of them do, although that doesn't mean they shouldn't.)
(Note that while a lot of these have pages, not all of them do, although that doesn't mean they shouldn't.)


== Using S-monzos to understand the significance of S-expressions ==
== Using S-factorizations to understand the significance of S-expressions ==
This section deals with the forms of the main 5 infinite comma families as expressed in terms of nearby harmonics in the harmonic series and as related to square-particulars; note that this uses a mathematical notation of [a, b, c, ...]^[x, y, z, ...] to denote a^x * b^y * c^z * ...
This section deals with the forms of the main 5 infinite comma families as expressed in terms of nearby harmonics in the harmonic series and as related to square-particulars; note that this uses a mathematical notation of [a, b, c, ...]^[x, y, z, ...] to denote a^x * b^y * c^z * ...


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</pre>
</pre>


This technique will be called "'''S-monzos'''", as it is a form analogous to monzos that is uniquely suited for interpreting the relationships described by '''S-expressions'''.
This technique will be called "'''S-factorizations'''", as it is uses a certain format for expressing factorization (analogous to [[monzo]]s) that is uniquely suited for interpreting the relationships described by '''S-expressions'''.
 
Note that the redundancy in these factorizations (in the sense that there are generators that are not linearly independent of the others) is a property that reflects the reality of [[#Equivalent S-expressions|equivalent S-expressions]].


The generalisation of this method using commutative group theory is discussed in [[square superparticular#Abstraction|the abstraction section of this page]].
The generalisation of this method using commutative group theory is discussed in [[square superparticular#Abstraction|the abstraction section of this page]].
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== Sk<sup>2</sup> * S(k + 1) and S(k - 1) * Sk<sup>2</sup> (lopsided commas) ==
== Sk<sup>2</sup> * S(k + 1) and S(k - 1) * Sk<sup>2</sup> (lopsided commas) ==


Using the clarity of S-monzos, we can show the interval relations implicated by these two new "lopsided" forms, which will make clear the reason for their name:
Using the clarity of S-factorizations, we can show the interval relations implicated by these two new "lopsided" forms, which will make clear the reason for their name:


S''k''<sup>2</sup> * S(''k''+1) = [''k''-1, ''k'', ''k''+1, ''k''+2]^(2[-1, 2, -1, 0] + [0, -1, 2, -1] = [-2, 4, -2, 0] + [0, -1, 2, -1] = [-2, 3, 0, -1]) implies:
S''k''<sup>2</sup> * S(''k''+1) = [''k''-1, ''k'', ''k''+1, ''k''+2]^(2[-1, 2, -1, 0] + [0, -1, 2, -1] = [-2, 4, -2, 0] + [0, -1, 2, -1] = [-2, 3, 0, -1]) implies:
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: An expression using the S''k'' shorthand notation corresponding strictly to multiplying and dividing only (arbitrary) square-particulars. S-expressions include singular square superparticulars and expressions for other superparticulars in terms of square superparticulars.
: An expression using the S''k'' shorthand notation corresponding strictly to multiplying and dividing only (arbitrary) square-particulars. S-expressions include singular square superparticulars and expressions for other superparticulars in terms of square superparticulars.


; S-monzo
; S-factorization
: An expression that takes a list of consecutive integer harmonics including the ''k''th harmonic and raises them to integer powers, analogous to a monzo but uniquely suited to analysing S-expressions.
: An expression that takes a list of consecutive integer harmonics including the ''k''th harmonic and raises them to integer powers, similar to a [[smonzo]] but uniquely suited to analysing S-expressions.
: For example: S''k'' = [''k''-1, ''k'', ''k''+1]^[-1, 2, -1] because S''k'' = (''k''-1)<sup>-1</sup>''k''<sup>2</sup>(''k''+1)<sup>-1</sup>.
: For example: S''k'' = [''k''-1, ''k'', ''k''+1]^[-1, 2, -1] because S''k'' = (''k''-1)<sup>-1</sup>''k''<sup>2</sup>(''k''+1)<sup>-1</sup>.


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</math>
</math>


Then (the analogues of) S-monzos correspond to the ''exponents'' of the generators, such that:
Then (the analogues of) S-factorizations correspond to the ''exponents'' of the generators, such that:


<math>
<math>
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This completes the analogy. What this means is:
This completes the analogy. What this means is:


Every infinite comma family defined in terms of an S-expression will have an infinite number of analogues, because of the maths of S-monzos continuing to work as expected.
Every infinite comma family defined in terms of an S-expression will have an infinite number of analogues, because of the maths of S-factorizations continuing to work as expected.


The meanings of these analogues are up to us to interpret, however. This brings us to applications, which we will examine next, with a focus on the musical ones:
The meanings of these analogues are up to us to interpret, however. This brings us to applications, which we will examine next, with a focus on the musical ones:
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=== h<sub>k</sub> = k ===
=== h<sub>k</sub> = k ===
The trivial example, equal to normal S-expressions and S-monzos, before abstraction.
The trivial example, equal to normal S-expressions and S-factorizations, before abstraction.


=== h<sub>k</sub> = 2k + 1 ===
=== h<sub>k</sub> = 2k + 1 ===
An analogy of S-expressions and S-monzos for [[EDT]]s which can be used as a corresponding [[RTT]] tool for when we only want to focus on the arithmetic of odds, using [[3/1]] as the new [[equave]].
An analogy of S-expressions and S-factorizations for [[EDT]]s which can be used as a corresponding [[RTT]] tool for when we only want to focus on the arithmetic of odds, using [[3/1]] as the new [[equave]].


A suggestion is to use the notation So''k'', if this is not unambiguous, with the letter "o" standing for "odd". Thus:
A suggestion is to use the notation So''k'', if this is not unambiguous, with the letter "o" standing for "odd". Thus:
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=== h<sub>k</sub> = (k + 1)/k ===
=== h<sub>k</sub> = (k + 1)/k ===
An analogy of S-expressions and S-monzos aiming at deeply faithful modelling of the harmonic series through modelling distances between superparticulars accurately.
An analogy of S-expressions and S-factorizations aiming at deeply faithful modelling of the harmonic series through modelling distances between superparticulars accurately.


A suggestion is to use the notation Ss''k'', if this is not unambiguous, with the letter "s" standing for "superparticular" or "super" generally.
A suggestion is to use the notation Ss''k'', if this is not unambiguous, with the letter "s" standing for "superparticular" or "super" generally.