31edo: Difference between revisions

Further wording refinements
Move temperament measures to RTT properties section
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== Just approximation ==
== Just approximation ==
=== Selected just intervals ===
=== 15-odd-limit interval mappings ===
==== 15-odd-limit interval mappings ====


The following table shows how [[15-odd-limit intervals]] are represented in 31edo. Prime harmonics are in '''bold'''; inconsistent intervals are in ''italic''.  
The following table shows how [[15-odd-limit intervals]] are represented in 31edo. Prime harmonics are in '''bold'''; inconsistent intervals are in ''italic''.  
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==== Selected 19-limit intervals ====
=== Selected 19-limit intervals ===
 
[[File:31-edo.svg|alt=alt : Your browser has no SVG support.]]
[[File:31-edo.svg|alt=alt : Your browser has no SVG support.]]
=== Temperament measures ===
The following table shows [[TE temperament measures]] (RMS normalized) of 31et.
{| class="wikitable center-all"
! colspan="2" |
! 3-limit
! 5-limit
! 7-limit
! 11-limit
! 13-limit
! 17-limit
|-
! colspan="2" |Octave stretch (¢)
| +1.63
| +0.98
| +0.83
| +1.21
| +0.50
| +0.039
|-
! rowspan="2" |Error
! [[TE error|absolute]] (¢)
| 1.64
| 1.63
| 1.43
| 1.49
| 2.07
| 2.23
|-
! [[TE simple badness|relative]] (%)
| 4.22
| 4.20
| 3.70
| 3.84
| 5.35
| 5.75
|}
* 31et is lower in relative error than any previous ETs in the 7-, 11-, 13-, and 17-limit. The next ETs in those subgroups are 72, 72, 41, and 46, respectively.


== Relationship to 12-edo ==
== Relationship to 12-edo ==
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== Regular temperament properties ==
== Regular temperament properties ==
31edo excels in the 2.5.7 subgroup (the JI chord 4:5:7 is represented highly [[consistent]]ly: to [[consistency#Consistency to distance d|distance]] 10.36). In 2.5.7 it tempers out the didacus comma [[3136/3125]] and {{monzo|-15 0 -2 7}} ([[823543/819200]]), thus also tempering out the very small [[rainy comma]], the simplest 2.5.7 comma tempered out by the 7-limit microtemperament [[171edo]]. In the 11-limit, 31edo can be defined as the unique temperament that tempers out [[81/80]], [[99/98]], [[121/120]] and [[126/125]], and it supports [[orwell]], [[mohajira]], and the relatively high-accuracy temperament [[miracle]]. In the [[13-limit]] 31edo doesn't do as well, but is the [[optimal patent val]] for the rank five temperament tempering out the 13-limit comma [[66/65]], which equates [[6/5]] and [[13/11]]. It also provides the optimal patent val for mohajira, squares and casablanca in the 11-limit and huygens/meantone, squares, winston, lupercalia and nightengale in the 13-limit.
{| class="wikitable center-4 center-5 center-6"
! rowspan="2" | Subgroup
! rowspan="2" | [[Comma list]]
! rowspan="2" | [[Mapping]]
! rowspan="2" | Optimal<br>8ve stretch (¢)
! colspan="2" | Tuning error
|-
! [[TE error|Absolute]] (¢)
! [[TE simple badness|Relative]] (%)
|-
| 2.3
| {{monzo| -49 31 }}
| [{{val| 31 49 }}]
| +1.63
| 1.64
| 4.22
|-
| 2.3.5
| 81/80, 393216/390625
| [{{val| 31 49 72 }}]
| +0.98
| 1.63
| 4.20
|-
| 2.3.5.7
| 81/80, 126/125, 1029/1024
| [{{val| 31 49 72 87 }}]
| +0.83
| 1.43
| 3.70
|-
| 2.3.5.7.11
| 81/80, 99/98, 121/120, 126/125
| [{{val| 31 49 72 87 107 }}]
| +1.21
| 1.49
| 3.84
|}
 
31et is lower in relative error than any previous equal temperaments in the 7-, 11-, 13-, and 17-limit. The next ETs in those subgroups are 72, 72, 41, and 46, respectively.
 
31edo excels in the 2.5.7 subgroup (the JI chord 4:5:7 is represented highly [[consistent]]ly: to [[consistency #Consistency to distance d|distance]] 10.36). In 2.5.7 it tempers out the didacus comma [[3136/3125]] and {{monzo|-15 0 -2 7}} ([[823543/819200]]), thus also tempering out the very small [[rainy comma]], the simplest 2.5.7 comma tempered out by the 7-limit microtemperament [[171edo]]. In the 11-limit, 31edo can be defined as the unique temperament that tempers out [[81/80]], [[99/98]], [[121/120]] and [[126/125]], and it supports [[orwell]], [[mohajira]], and the relatively high-accuracy temperament [[miracle]]. In the [[13-limit]] 31edo doesn't do as well, but is the [[optimal patent val]] for the rank five temperament tempering out the 13-limit comma [[66/65]], which equates [[6/5]] and [[13/11]]. It also provides the optimal patent val for mohajira, squares and casablanca in the 11-limit and huygens/meantone, squares, winston, lupercalia and nightengale in the 13-limit.


=== Commas ===
=== Commas ===