Temperament mapping matrix: Difference between revisions

Wikispaces>mbattaglia1
**Imported revision 355698700 - Original comment: **
Wikispaces>genewardsmith
**Imported revision 355718280 - 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:mbattaglia1|mbattaglia1]] and made on <tt>2012-07-31 11:16:19 UTC</tt>.<br>
: This revision was by author [[User:genewardsmith|genewardsmith]] and made on <tt>2012-07-31 13:07:10 UTC</tt>.<br>
: The original revision id was <tt>355698700</tt>.<br>
: The original revision id was <tt>355718280</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">=Basics=  
<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">=Basics=  
The multiplicative group of any set of rational numbers, which is an r-rank free abelian group, also naturally has the structure of being a Z-module. Thus, a [[Regular Temperaments|regular temperament]], which is a group homomorphism **T**: J -&gt; K from the group J of JI rationals to a group K of tempered intervals, also has the structure of being a module homomorphism between Z-modules. This homomorphism can also be represented by a integer matrix, called a **temperament mapping matrix**; when context is clear enough it's also sometimes just called a **mapping matrix** for the temperament in question. Since there is more than one type of mapping matrix which appears in music theory, it has also more rarely been called a "monzo-map" or **M-map** when context demands, as opposed to the [[Subgroup Mapping Matrices (V-maps)|V-map]] which is a mapping on vals.
The multiplicative group of any set of rational numbers, which is an r-rank free abelian group, also naturally has the structure of being a Z-module. Thus, a [[Regular Temperaments|regular temperament]], or more precisely an [[abstract regular temperament]], is a group homomorphism **T**: J K from the group J of JI rationals to a group K of tempered intervals, also has the structure of being a Z-module homomorphism. This homomorphism can also be represented by a integer matrix, called a **temperament mapping matrix**; when context is clear enough it's also sometimes just called a **mapping matrix** for the temperament in question. Since there is more than one type of mapping matrix which appears in music theory, it has also more rarely been called a "monzo-map" or **M-map** when context demands, as opposed to the [[Subgroup Mapping Matrices (V-maps)|V-map]] which is a mapping on vals.


Assuming we use the convention that row matrices represent vals and column matrices represent monzos, then a matrix M is said to be a mapping matrix for a temperament T if and only if the null module of M consists of the kernel of T, M is of full row rank, and the rows of M generate a submodule which is [[Saturation|saturated]]. There is generally not a unique matrix M satisfying this definition for arbitrary temperament T, as for any M which is a valid mapping for T, any matrix U*M where U is unimodular will also be a valid mapping for T. The different mapping matrices obtainable in this way still temper out the same commas, but differ in the choice of basis for the tempered interval module.
Assuming we use the convention that row matrices represent vals and column matrices represent monzos, then a matrix M is said to be a mapping matrix for a temperament T if and only if the null module of M consists of the kernel of T, M is of full row rank, and the rows of M generate a submodule which is [[Saturation|saturated]]. There is generally not a unique matrix M satisfying this definition for arbitrary temperament T, as for any M which is a valid mapping for T, any matrix U*M where U is unimodular will also be a valid mapping for T. The different mapping matrices obtainable in this way still temper out the same commas, but differ in the choice of basis for the tempered interval module.
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=Dual Transformation=  
=Dual Transformation=  
Any mapping matrix can be said to represent a linear map **M:** J -&gt; K, where J is a module of JI intervals and K is a module of tempered intervals. There is thus an associated dual transformation **M*:** K* -&gt; J*, where J* and K* are the dual modules to J and K, respectively. J* is the module of vals on J, and K* is the module of [[xenharmonic/tmonzos and tvals|tvals]] on K, so **M*** represents a linear transformation mapping from tvals to vals. This mapping will generally be injective but not surjective; its image is the submodule of vals supporting the associated temperament, and no two tvals map to the same val.
Any mapping matrix can be said to represent a linear map **M:** J K, where J is a module of JI intervals and K is a module of tempered intervals. There is thus an associated dual transformation **M*:** K* J*, where J* and K* are the dual modules to J and K, respectively. J* is the module of vals on J, and K* is the module of [[xenharmonic/tmonzos and tvals|tvals]] on K, so **M*** represents a linear transformation mapping from tvals to vals. This mapping will generally be injective but not surjective; its image is the submodule of vals supporting the associated temperament, and no two tvals map to the same val.


These two transformations correspond to different types of matrix multiplication: the ordinary transformation **M** corresponds to multiplication with the mapping on the left and a matrix whose columns are monzos on the right, and the dual transformation **M*** corresponds to multiplication with the mapping on the right and a matrix whose rows are tvals on the left.
These two transformations correspond to different types of matrix multiplication: the ordinary transformation **M** corresponds to multiplication with the mapping on the left and a matrix whose columns are monzos on the right, and the dual transformation **M*** corresponds to multiplication with the mapping on the right and a matrix whose rows are tvals on the left.
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<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;Temperament Mapping Matrices (M-maps)&lt;/title&gt;&lt;/head&gt;&lt;body&gt;&lt;!-- ws:start:WikiTextHeadingRule:5:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc0"&gt;&lt;a name="Basics"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:5 --&gt;Basics&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;Temperament Mapping Matrices (M-maps)&lt;/title&gt;&lt;/head&gt;&lt;body&gt;&lt;!-- ws:start:WikiTextHeadingRule:5:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc0"&gt;&lt;a name="Basics"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:5 --&gt;Basics&lt;/h1&gt;
  The multiplicative group of any set of rational numbers, which is an r-rank free abelian group, also naturally has the structure of being a Z-module. Thus, a &lt;a class="wiki_link" href="/Regular%20Temperaments"&gt;regular temperament&lt;/a&gt;, which is a group homomorphism &lt;strong&gt;T&lt;/strong&gt;: J -&amp;gt; K from the group J of JI rationals to a group K of tempered intervals, also has the structure of being a module homomorphism between Z-modules. This homomorphism can also be represented by a integer matrix, called a &lt;strong&gt;temperament mapping matrix&lt;/strong&gt;; when context is clear enough it's also sometimes just called a &lt;strong&gt;mapping matrix&lt;/strong&gt; for the temperament in question. Since there is more than one type of mapping matrix which appears in music theory, it has also more rarely been called a &amp;quot;monzo-map&amp;quot; or &lt;strong&gt;M-map&lt;/strong&gt; when context demands, as opposed to the &lt;a class="wiki_link" href="/Subgroup%20Mapping%20Matrices%20%28V-maps%29"&gt;V-map&lt;/a&gt; which is a mapping on vals.&lt;br /&gt;
  The multiplicative group of any set of rational numbers, which is an r-rank free abelian group, also naturally has the structure of being a Z-module. Thus, a &lt;a class="wiki_link" href="/Regular%20Temperaments"&gt;regular temperament&lt;/a&gt;, or more precisely an &lt;a class="wiki_link" href="/abstract%20regular%20temperament"&gt;abstract regular temperament&lt;/a&gt;, is a group homomorphism &lt;strong&gt;T&lt;/strong&gt;: J K from the group J of JI rationals to a group K of tempered intervals, also has the structure of being a Z-module homomorphism. This homomorphism can also be represented by a integer matrix, called a &lt;strong&gt;temperament mapping matrix&lt;/strong&gt;; when context is clear enough it's also sometimes just called a &lt;strong&gt;mapping matrix&lt;/strong&gt; for the temperament in question. Since there is more than one type of mapping matrix which appears in music theory, it has also more rarely been called a &amp;quot;monzo-map&amp;quot; or &lt;strong&gt;M-map&lt;/strong&gt; when context demands, as opposed to the &lt;a class="wiki_link" href="/Subgroup%20Mapping%20Matrices%20%28V-maps%29"&gt;V-map&lt;/a&gt; which is a mapping on vals.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
Assuming we use the convention that row matrices represent vals and column matrices represent monzos, then a matrix M is said to be a mapping matrix for a temperament T if and only if the null module of M consists of the kernel of T, M is of full row rank, and the rows of M generate a submodule which is &lt;a class="wiki_link" href="/Saturation"&gt;saturated&lt;/a&gt;. There is generally not a unique matrix M satisfying this definition for arbitrary temperament T, as for any M which is a valid mapping for T, any matrix U*M where U is unimodular will also be a valid mapping for T. The different mapping matrices obtainable in this way still temper out the same commas, but differ in the choice of basis for the tempered interval module.&lt;br /&gt;
Assuming we use the convention that row matrices represent vals and column matrices represent monzos, then a matrix M is said to be a mapping matrix for a temperament T if and only if the null module of M consists of the kernel of T, M is of full row rank, and the rows of M generate a submodule which is &lt;a class="wiki_link" href="/Saturation"&gt;saturated&lt;/a&gt;. There is generally not a unique matrix M satisfying this definition for arbitrary temperament T, as for any M which is a valid mapping for T, any matrix U*M where U is unimodular will also be a valid mapping for T. The different mapping matrices obtainable in this way still temper out the same commas, but differ in the choice of basis for the tempered interval module.&lt;br /&gt;
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&lt;br /&gt;
&lt;br /&gt;
&lt;!-- ws:start:WikiTextHeadingRule:7:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc1"&gt;&lt;a name="Dual Transformation"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:7 --&gt;Dual Transformation&lt;/h1&gt;
&lt;!-- ws:start:WikiTextHeadingRule:7:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc1"&gt;&lt;a name="Dual Transformation"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:7 --&gt;Dual Transformation&lt;/h1&gt;
  Any mapping matrix can be said to represent a linear map &lt;strong&gt;M:&lt;/strong&gt; J -&amp;gt; K, where J is a module of JI intervals and K is a module of tempered intervals. There is thus an associated dual transformation &lt;strong&gt;M*:&lt;/strong&gt; K* -&amp;gt; J*, where J* and K* are the dual modules to J and K, respectively. J* is the module of vals on J, and K* is the module of &lt;a class="wiki_link" href="http://xenharmonic.wikispaces.com/tmonzos%20and%20tvals"&gt;tvals&lt;/a&gt; on K, so &lt;strong&gt;M&lt;/strong&gt;* represents a linear transformation mapping from tvals to vals. This mapping will generally be injective but not surjective; its image is the submodule of vals supporting the associated temperament, and no two tvals map to the same val.&lt;br /&gt;
  Any mapping matrix can be said to represent a linear map &lt;strong&gt;M:&lt;/strong&gt; J K, where J is a module of JI intervals and K is a module of tempered intervals. There is thus an associated dual transformation &lt;strong&gt;M*:&lt;/strong&gt; K* J*, where J* and K* are the dual modules to J and K, respectively. J* is the module of vals on J, and K* is the module of &lt;a class="wiki_link" href="http://xenharmonic.wikispaces.com/tmonzos%20and%20tvals"&gt;tvals&lt;/a&gt; on K, so &lt;strong&gt;M&lt;/strong&gt;* represents a linear transformation mapping from tvals to vals. This mapping will generally be injective but not surjective; its image is the submodule of vals supporting the associated temperament, and no two tvals map to the same val.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
These two transformations correspond to different types of matrix multiplication: the ordinary transformation &lt;strong&gt;M&lt;/strong&gt; corresponds to multiplication with the mapping on the left and a matrix whose columns are monzos on the right, and the dual transformation &lt;strong&gt;M&lt;/strong&gt;* corresponds to multiplication with the mapping on the right and a matrix whose rows are tvals on the left.&lt;br /&gt;
These two transformations correspond to different types of matrix multiplication: the ordinary transformation &lt;strong&gt;M&lt;/strong&gt; corresponds to multiplication with the mapping on the left and a matrix whose columns are monzos on the right, and the dual transformation &lt;strong&gt;M&lt;/strong&gt;* corresponds to multiplication with the mapping on the right and a matrix whose rows are tvals on the left.&lt;br /&gt;