Porcupine family: Difference between revisions

Porcupine: complete the extensions
Sort the extensions out and move oxygen to very low accuracy temps
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=== Overview to extensions ===
=== Overview to extensions ===
==== 7-limit extensions ====
==== 7-limit extensions ====
The second comma defines which [[7-limit]] family member we are looking at. That means
The second comma defines which [[7-limit]] family member we are looking at.  
* [[64/63]], the archytas comma, for [[#Septimal porcupine|septimal porcupine]],
* [[#Hystrix|Hystrix]] adds [[36/35]], the mint comma, for a tuning sharp of 8d-edo;
* [[225/224]], the marvel comma, for [[#Porky|porky]],
* [[#Opossum|Opossum]] adds [[28/27]], the trienstonic comma, for a tuning between 8d-edo and 15edo;
* [[525/512]], the avicennma, for [[#Coendou|coendou]],
* [[#Septimal porcupine|Septimal porcupine]] adds [[64/63]], the archytas comma, for a tuning between 15edo and 22edo;
* [[36/35]], the mint comma, for [[#Hystrix|hystrix]],
* [[#Porky|Porky]] adds [[225/224]], the marvel comma, for a tuning between 22edo and 29edo;
* [[28/27]], the trienstonic comma, for [[#Opossum|opossum]], and
* [[#Coendou|Coendou]] adds [[525/512]], the avicennma, for a tuning flat of 29edo.  
* [[21/20]], the septisemi comma, for [[#Oxygen|oxygen]].  


Those all share the same generator with porcupine. Alternatively you could choose
Those all share the same generator with porcupine.  
* [[49/48]], the semaphoresma, for [[#Nautilus|nautilus]],
* [[50/49]], the jubilisma, for [[#Hedgehog|hedgehog]],
* [[686/675]], the senga, for [[#Ammonite|ammonite]], and
* [[1728/1715]], the orwellisma, for [[#Ceratitid|ceratitid]].  


Those split the generators and/or periods in various ways.  
[[#Nautilus|nautilus]] tempers out [[49/48]] and splits the generator in two. [[#Hedgehog|hedgehog]] tempers out [[50/49]] with a semi-octave period. Finally, [[#Ammonite|ammonite]] tempers out [[686/675]] and [[#Ceratitid|ceratitid]] tempers out [[1728/1715]]. Those split the generator in three.  


Temperaments discussed elsewhere include [[7th-octave temperaments #Jamesbond|jamesbond]].
Temperaments discussed elsewhere include:
* [[Oxygen]] → [[Very low accuracy temperaments #Oxygen|Very low accuracy temperaments]].
* [[Jamesbond]] → [[7th-octave temperaments #Jamesbond|7th-octave temperaments]].


==== Subgroup extensions ====
==== Subgroup extensions ====
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Badness (Smith): 0.026790
Badness (Smith): 0.026790
== Oxygen ==
Oxygen is perhaps not meant to be used as a serious temperament of harmony. Its comma basis suggests potential utility to construct [[Fokker block]]s.
[[Subgroup]]: 2.3.5.7
[[Comma list]]: 21/20, 175/162
{{Mapping|legend=1| 1 2 3 3 | 0 -3 -5 -2 }}
{{Multival|legend=1| 3 5 2 1 -5 -9 }}
[[Optimal tuning]]s:
* [[CTE]]: ~2 = 1200.000, ~10/9 = 161.341
: [[error map]]: {{val| 0.000 +14.023 +6.982 -91.507 }}
* [[POTE]]: ~2 = 1200.000, ~10/9 = 169.112
: error map: {{val| 0.000 -9.291 -31.873 -107.050 }}
{{Optimal ET sequence|legend=1| 1c, …, 6bcd, 7d }}
[[Badness]] (Smith): 0.059866


== Hedgehog ==
== Hedgehog ==