Ploidacot: Difference between revisions

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If [[3/2]] is represented by a linearly independent element to the ploid, there is a number of ploids which when added to 3/2 gives the interval which splits into the largest number of parts by the temperament. Each of these parts is called a '''cot''' or '''cotyledon''' and the ploidacot system uses one or more Greek letters to describe the smallest number of ploids should be added to 3/2 to form a whole number of cots, and this number of cots is indicated by a Greek numerical prefix.
If [[3/2]] is represented by a linearly independent element to the ploid, there is a number of ploids which when added to 3/2 gives the interval which splits into the largest number of parts by the temperament. Each of these parts is called a '''cot''' or '''cotyledon''' and the ploidacot system uses one or more Greek letters to describe the smallest number of ploids should be added to 3/2 to form a whole number of cots, and this number of cots is indicated by a Greek numerical prefix.


The Greek letter prefixes follow the ancient gematria/isopsephic system, so 6 is digamma, 7 is zeta, 8 is eta, etc.
Temperaments where the image of 3/2 is a whole number of ploids are called '''acot'''.


Temperaments where the image of 3/2 is a whole number of ploids are called '''acot'''.
=== Greek letter prefixes ===
The Greek letter prefixes follow the ancient gematria/isopsephic system, detailed below:
{| class="wikitable"
|+Greek letter prefixes in ploidacot
!Number ''n''
!1
!2
!3
!4
!5
!6
!7
!8
!9
|-
|Prefix for ''n''
|alpha
|beta
|gamma
|delta
|epsilon
|digamma
|zeta
|eta
|theta
|-
|Prefix for 10*''n''
|iota
|kappa
|lambda
|mu
|nu
|xi
|omicron
|pi
|sampi
|-
|Prefix for ''n''+10
|iota-alpha
|iota-beta
|iota-gamma
|iota-delta
|iota-epsilon
|iota-digamma
|iota-zeta
|iota-eta
|iota-theta
|}
Prefixes for numbers between 21 and 99 are constructed the same way as number words in English, for instance 21 is kappa-alpha and 99 is sampi-theta.


== Examples ==
== Examples ==

Revision as of 01:04, 20 August 2023

The ploidacot system is a scale naming scheme based on the classification of rank-2 temperaments by pergen, i.e. how a temperament can be thought of as a union of copies of Pythagorean tuning. It is a canonical naming scheme for pergen squares in that every pergen square that covers both 2/1 and 3/2 has a unique name in the ploidacot system.

The ploidacot system was developed by Praveen Venkataramana.

Ploids

Any rank-2 temperament must split the octave into a number of ploids, for instance pajara divides the octave into two so it's diploid. Temperaments that don't divide the octave are called haploid.

Cots

If 3/2 is represented by a linearly independent element to the ploid, there is a number of ploids which when added to 3/2 gives the interval which splits into the largest number of parts by the temperament. Each of these parts is called a cot or cotyledon and the ploidacot system uses one or more Greek letters to describe the smallest number of ploids should be added to 3/2 to form a whole number of cots, and this number of cots is indicated by a Greek numerical prefix.

Temperaments where the image of 3/2 is a whole number of ploids are called acot.

Greek letter prefixes

The Greek letter prefixes follow the ancient gematria/isopsephic system, detailed below:

Greek letter prefixes in ploidacot
Number n 1 2 3 4 5 6 7 8 9
Prefix for n alpha beta gamma delta epsilon digamma zeta eta theta
Prefix for 10*n iota kappa lambda mu nu xi omicron pi sampi
Prefix for n+10 iota-alpha iota-beta iota-gamma iota-delta iota-epsilon iota-digamma iota-zeta iota-eta iota-theta

Prefixes for numbers between 21 and 99 are constructed the same way as number words in English, for instance 21 is kappa-alpha and 99 is sampi-theta.

Examples

Notation

Todo: come up with canonical ups and downs notation systems for pergen squares