The wedgie: Difference between revisions

Wikispaces>genewardsmith
**Imported revision 289829061 - Original comment: **
Wikispaces>genewardsmith
**Imported revision 289850121 - Original comment: **
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<h2>IMPORTED REVISION FROM WIKISPACES</h2>
<h2>IMPORTED REVISION FROM WIKISPACES</h2>
This is an imported revision from Wikispaces. The revision metadata is included below for reference:<br>
This is an imported revision from Wikispaces. The revision metadata is included below for reference:<br>
: This revision was by author [[User:genewardsmith|genewardsmith]] and made on <tt>2012-01-05 13:10:16 UTC</tt>.<br>
: This revision was by author [[User:genewardsmith|genewardsmith]] and made on <tt>2012-01-05 14:12:11 UTC</tt>.<br>
: The original revision id was <tt>289829061</tt>.<br>
: The original revision id was <tt>289850121</tt>.<br>
: The revision comment was: <tt></tt><br>
: The revision comment was: <tt></tt><br>
The revision contents are below, presented both in the original Wikispaces Wikitext format, and in HTML exactly as Wikispaces rendered it.<br>
The revision contents are below, presented both in the original Wikispaces Wikitext format, and in HTML exactly as Wikispaces rendered it.<br>
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+(\frac{f}{q_5q_7}-\frac{e}{q_3q_7}+\frac{d}{q_3q_5})^2 = 4 B^2
+(\frac{f}{q_5q_7}-\frac{e}{q_3q_7}+\frac{d}{q_3q_5})^2 = 4 B^2
[[math]]
[[math]]
For this we can conclude that d, e and f satisfy |d - q3b + q5a| ≤ 2B√q3q5, |e - q3c + q7a| ≤ 2B√q3q7 and |f - q5c + q7d| ≤ 2B√q5q7. This has an interesting interpretation: since &lt;1 q3 q5 q7|∧&lt;0 a b c| = &lt;&lt;a  b  c  q3b-q5a  q3c-q7a  q5c-q7b||, if B ≤ 1/(4√q5q7), then the full wedgie can be recovered from the octave equivalent (OE) portion of the wedgie simply by wedging it with &lt;1 q3 q5 q7| and rounding to the nearest integer. This is not a very serious constraint to place on simple badness; it seems unlikely anyone would be interested in a temperament which did not fall well under this low standard. Hence we may compile lists of reasonable temperaments by presuming "reasonable" requires this bound to be met, searching through triples &lt;&lt;a b d ...|| up to some complexity bound, wedging with &lt;1 q3 q5 q7| and rounding, then checking if the GCD is one and the Pfaffian af-be+cd is zero. Then we may toss everthing which does not meet the bound on simple badness; however, for a reasonable list we will want a tighter bound.




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+(\frac{f}{q_5q_7}-\frac{e}{q_3q_7}+\frac{d}{q_3q_5})^2 = 4 B^2&amp;lt;br/&amp;gt;[[math]]
+(\frac{f}{q_5q_7}-\frac{e}{q_3q_7}+\frac{d}{q_3q_5})^2 = 4 B^2&amp;lt;br/&amp;gt;[[math]]
  --&gt;&lt;script type="math/tex"&gt;\displaystyle (\frac{d}{q_3q_5}-\frac{b}{q_5}+\frac{a}{q_3})^2+(\frac{e}{q_3q_7}-\frac{c}{q_7}+\frac{a}{q_3})^2+(\frac{f}{q_5q_7}-\frac{c}{q_7}+\frac{b}{q_5})^2 \\
  --&gt;&lt;script type="math/tex"&gt;\displaystyle (\frac{d}{q_3q_5}-\frac{b}{q_5}+\frac{a}{q_3})^2+(\frac{e}{q_3q_7}-\frac{c}{q_7}+\frac{a}{q_3})^2+(\frac{f}{q_5q_7}-\frac{c}{q_7}+\frac{b}{q_5})^2 \\
+(\frac{f}{q_5q_7}-\frac{e}{q_3q_7}+\frac{d}{q_3q_5})^2 = 4 B^2&lt;/script&gt;&lt;!-- ws:end:WikiTextMathRule:0 --&gt;&lt;/body&gt;&lt;/html&gt;</pre></div>
+(\frac{f}{q_5q_7}-\frac{e}{q_3q_7}+\frac{d}{q_3q_5})^2 = 4 B^2&lt;/script&gt;&lt;!-- ws:end:WikiTextMathRule:0 --&gt;&lt;br /&gt;
&lt;br /&gt;
For this we can conclude that d, e and f satisfy |d - q3b + q5a| ≤ 2B√q3q5, |e - q3c + q7a| ≤ 2B√q3q7 and |f - q5c + q7d| ≤ 2B√q5q7. This has an interesting interpretation: since &amp;lt;1 q3 q5 q7|∧&amp;lt;0 a b c| = &amp;lt;&amp;lt;a  b  c  q3b-q5a  q3c-q7a  q5c-q7b||, if B ≤ 1/(4√q5q7), then the full wedgie can be recovered from the octave equivalent (OE) portion of the wedgie simply by wedging it with &amp;lt;1 q3 q5 q7| and rounding to the nearest integer. This is not a very serious constraint to place on simple badness; it seems unlikely anyone would be interested in a temperament which did not fall well under this low standard. Hence we may compile lists of reasonable temperaments by presuming &amp;quot;reasonable&amp;quot; requires this bound to be met, searching through triples &amp;lt;&amp;lt;a b d ...|| up to some complexity bound, wedging with &amp;lt;1 q3 q5 q7| and rounding, then checking if the GCD is one and the Pfaffian af-be+cd is zero. Then we may toss everthing which does not meet the bound on simple badness; however, for a reasonable list we will want a tighter bound.&lt;/body&gt;&lt;/html&gt;</pre></div>