Height: Difference between revisions

Wikispaces>guest
**Imported revision 362749812 - Original comment: **
Wikispaces>Sarzadoce
**Imported revision 363105768 - Original comment: **
Line 1: Line 1:
<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:guest|guest]] and made on <tt>2012-09-07 03:49:45 UTC</tt>.<br>
: This revision was by author [[User:Sarzadoce|Sarzadoce]] and made on <tt>2012-09-08 23:32:31 UTC</tt>.<br>
: The original revision id was <tt>362749812</tt>.<br>
: The original revision id was <tt>363105768</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>
<h4>Original Wikitext content:</h4>
<h4>Original Wikitext content:</h4>
<div style="width:100%; max-height:400pt; overflow:auto; background-color:#f8f9fa; border: 1px solid #eaecf0; padding:0em"><pre style="margin:0px;border:none;background:none;word-wrap:break-word;white-space: pre-wrap ! important" class="old-revision-html">=Definition:=  
<div style="width:100%; max-height:400pt; overflow:auto; background-color:#f8f9fa; border: 1px solid #eaecf0; padding:0em"><pre style="margin:0px;border:none;background:none;word-wrap:break-word;white-space: pre-wrap ! important" class="old-revision-html">=Definition:=  
A **height** is a function on an abelian group which maps elements to real numbers, yielding a type of complexity measurement. Since the (non-zero) rationals form an abelian group under multiplication, we can assign each element a height, and hence a complexity. While there is no concensus on the restrictions of a height, we will attempt to create a definition which is practical for musical purposes.
A **height** is a function on an abelian group which maps elements to real numbers, yielding a type of complexity measurement. Since the positive rationals form an abelian group under multiplication, we can assign each element a height, and hence a complexity. While there is no concensus on the restrictions of a height, we will attempt to create a definition which is practical for musical purposes.


A height function H(q) on the rationals q should fulfill the following criteria:
A height function H(q) on the positive rationals q should fulfill the following criteria:
# Given any constant C, there are finitely many elements q such that H(q) &lt;= C.
# Given any constant C, there are finitely many elements q such that H(q) &lt;= C.
# There is a unique constant K such that H(q) &gt;= K, for all q.
# There is a unique constant K such that H(q) &gt;= K, for all q.
# H(q) = H(1/q)
# H(q) = H(1/q)
# H(q^n) &gt;= H(q) for any non-negative integer n


Since any rational q can be rewritten as a fraction n/d, we may sub this into the above equation to get H(n/d) = H(d/n). This relation is extremely useful - it tells us that we can switch n and d without any consequences on the outcome of the height.
Since any rational q can be rewritten as a fraction n/d, we may sub this into the above equation to get H(n/d) = H(d/n). This relation is extremely useful - it tells us that we can switch n and d without any consequences on the outcome of the height.
Line 68: Line 69:
<h4>Original HTML content:</h4>
<h4>Original HTML content:</h4>
<div style="width:100%; max-height:400pt; overflow:auto; background-color:#f8f9fa; border: 1px solid #eaecf0; padding:0em"><pre style="margin:0px;border:none;background:none;word-wrap:break-word;width:200%;white-space: pre-wrap ! important" class="old-revision-html">&lt;html&gt;&lt;head&gt;&lt;title&gt;Height&lt;/title&gt;&lt;/head&gt;&lt;body&gt;&lt;!-- ws:start:WikiTextHeadingRule:16:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc0"&gt;&lt;a name="Definition:"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:16 --&gt;Definition:&lt;/h1&gt;
<div style="width:100%; max-height:400pt; overflow:auto; background-color:#f8f9fa; border: 1px solid #eaecf0; padding:0em"><pre style="margin:0px;border:none;background:none;word-wrap:break-word;width:200%;white-space: pre-wrap ! important" class="old-revision-html">&lt;html&gt;&lt;head&gt;&lt;title&gt;Height&lt;/title&gt;&lt;/head&gt;&lt;body&gt;&lt;!-- ws:start:WikiTextHeadingRule:16:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc0"&gt;&lt;a name="Definition:"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:16 --&gt;Definition:&lt;/h1&gt;
  A &lt;strong&gt;height&lt;/strong&gt; is a function on an abelian group which maps elements to real numbers, yielding a type of complexity measurement. Since the (non-zero) rationals form an abelian group under multiplication, we can assign each element a height, and hence a complexity. While there is no concensus on the restrictions of a height, we will attempt to create a definition which is practical for musical purposes.&lt;br /&gt;
  A &lt;strong&gt;height&lt;/strong&gt; is a function on an abelian group which maps elements to real numbers, yielding a type of complexity measurement. Since the positive rationals form an abelian group under multiplication, we can assign each element a height, and hence a complexity. While there is no concensus on the restrictions of a height, we will attempt to create a definition which is practical for musical purposes.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
A height function H(q) on the rationals q should fulfill the following criteria:&lt;br /&gt;
A height function H(q) on the positive rationals q should fulfill the following criteria:&lt;br /&gt;
&lt;ol&gt;&lt;li&gt;Given any constant C, there are finitely many elements q such that H(q) &amp;lt;= C.&lt;/li&gt;&lt;li&gt;There is a unique constant K such that H(q) &amp;gt;= K, for all q.&lt;/li&gt;&lt;li&gt;H(q) = H(1/q)&lt;/li&gt;&lt;/ol&gt;&lt;br /&gt;
&lt;ol&gt;&lt;li&gt;Given any constant C, there are finitely many elements q such that H(q) &amp;lt;= C.&lt;/li&gt;&lt;li&gt;There is a unique constant K such that H(q) &amp;gt;= K, for all q.&lt;/li&gt;&lt;li&gt;H(q) = H(1/q)&lt;/li&gt;&lt;li&gt;H(q^n) &amp;gt;= H(q) for any non-negative integer n&lt;/li&gt;&lt;/ol&gt;&lt;br /&gt;
Since any rational q can be rewritten as a fraction n/d, we may sub this into the above equation to get H(n/d) = H(d/n). This relation is extremely useful - it tells us that we can switch n and d without any consequences on the outcome of the height.&lt;br /&gt;
Since any rational q can be rewritten as a fraction n/d, we may sub this into the above equation to get H(n/d) = H(d/n). This relation is extremely useful - it tells us that we can switch n and d without any consequences on the outcome of the height.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;