Monzos and interval space: Difference between revisions
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Wikispaces>genewardsmith **Imported revision 307490684 - Original comment: ** |
Wikispaces>genewardsmith **Imported revision 307514102 - 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>2012-03- | : This revision was by author [[User:genewardsmith|genewardsmith]] and made on <tt>2012-03-04 02:48:05 UTC</tt>.<br> | ||
: The original revision id was <tt> | : The original revision id was <tt>307514102</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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[[math]] | [[math]] | ||
which is a [[http://en.wikipedia.org/wiki/Normed_vector_space|vector space norm]]; hence we may embed the p-limit monzos into a normed vector I space of dimension n = pi(p) via a map M:monzos -> I. The monzos under this embedding now define a [[http://en.wikipedia.org/wiki/Lattice_%28group%29|lattice]], which is a discrete subgroup spanning the finite dimensional real normed vector space I. If we change coordinates by multiplying values in the coordinate belonging to the prime k by log2(k), then the norm becomes the standard [[http://mathworld.wolfram.com/L1-Norm.html|L1 norm]]. This vector space is Tenney interval space, and the transformed coordinates with the standard L1 norm form the standard basis for Tenney space. It should be noted that while monzos correspond uniquely to positive real numbers (always rational numbers in the case of monzos), vectors in Tenney space do not. For instance, while |1 0> represents 2, so does |0 log3(2)>. | which is a [[http://en.wikipedia.org/wiki/Normed_vector_space|vector space norm]]; hence we may [[http://en.wikipedia.org/wiki/Embedding|embed]] the p-limit monzos into a normed vector I space of dimension n = pi(p) via a map M:monzos -> I. The monzos under this embedding now define a [[http://en.wikipedia.org/wiki/Lattice_%28group%29|lattice]], which is a discrete subgroup spanning the finite dimensional real normed vector space I. If we change coordinates by multiplying values in the coordinate belonging to the prime k by log2(k), then the norm becomes the standard [[http://mathworld.wolfram.com/L1-Norm.html|L1 norm]]. This vector space is Tenney interval space, and the transformed coordinates with the standard L1 norm form the standard basis for Tenney space. It should be noted that while monzos correspond uniquely to positive real numbers (always rational numbers in the case of monzos), vectors in Tenney space do not. For instance, while |1 0> represents 2, so does |0 log3(2)>. | ||
Because of the mathematical advantages of Euclidean norms, a Euclidean norm is often placed on the vectors in interval space instead of an L1 norm, in which case we have [[Tenney-Euclidean metrics|Tenney-Euclidean interval space]] instead of Tenney interval space. Explicitly, if we take the monzo |e2 e3 ... ep> then the Tenney-Euclidean norm, or TE norm, of it is | Because of the mathematical advantages of Euclidean norms, a Euclidean norm is often placed on the vectors in interval space instead of an L1 norm, in which case we have [[Tenney-Euclidean metrics|Tenney-Euclidean interval space]] instead of Tenney interval space. Explicitly, if we take the monzo |e2 e3 ... ep> then the Tenney-Euclidean norm, or TE norm, of it is | ||
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--><script type="math/tex">\| |e_2 \, e_3 \dotso e_p \rangle \| = |e_2| + |e_3| \log_2 3 + \dotsb + |e_p| \log_2 p</script><!-- ws:end:WikiTextMathRule:2 --><br /> | --><script type="math/tex">\| |e_2 \, e_3 \dotso e_p \rangle \| = |e_2| + |e_3| \log_2 3 + \dotsb + |e_p| \log_2 p</script><!-- ws:end:WikiTextMathRule:2 --><br /> | ||
<br /> | <br /> | ||
which is a <a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Normed_vector_space" rel="nofollow">vector space norm</a>; hence we may embed the p-limit monzos into a normed vector I space of dimension n = pi(p) via a map M:monzos -&gt; I. The monzos under this embedding now define a <a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Lattice_%28group%29" rel="nofollow">lattice</a>, which is a discrete subgroup spanning the finite dimensional real normed vector space I. If we change coordinates by multiplying values in the coordinate belonging to the prime k by log2(k), then the norm becomes the standard <a class="wiki_link_ext" href="http://mathworld.wolfram.com/L1-Norm.html" rel="nofollow">L1 norm</a>. This vector space is Tenney interval space, and the transformed coordinates with the standard L1 norm form the standard basis for Tenney space. It should be noted that while monzos correspond uniquely to positive real numbers (always rational numbers in the case of monzos), vectors in Tenney space do not. For instance, while |1 0&gt; represents 2, so does |0 log3(2)&gt;.<br /> | which is a <a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Normed_vector_space" rel="nofollow">vector space norm</a>; hence we may <a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Embedding" rel="nofollow">embed</a> the p-limit monzos into a normed vector I space of dimension n = pi(p) via a map M:monzos -&gt; I. The monzos under this embedding now define a <a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Lattice_%28group%29" rel="nofollow">lattice</a>, which is a discrete subgroup spanning the finite dimensional real normed vector space I. If we change coordinates by multiplying values in the coordinate belonging to the prime k by log2(k), then the norm becomes the standard <a class="wiki_link_ext" href="http://mathworld.wolfram.com/L1-Norm.html" rel="nofollow">L1 norm</a>. This vector space is Tenney interval space, and the transformed coordinates with the standard L1 norm form the standard basis for Tenney space. It should be noted that while monzos correspond uniquely to positive real numbers (always rational numbers in the case of monzos), vectors in Tenney space do not. For instance, while |1 0&gt; represents 2, so does |0 log3(2)&gt;.<br /> | ||
<br /> | <br /> | ||
Because of the mathematical advantages of Euclidean norms, a Euclidean norm is often placed on the vectors in interval space instead of an L1 norm, in which case we have <a class="wiki_link" href="/Tenney-Euclidean%20metrics">Tenney-Euclidean interval space</a> instead of Tenney interval space. Explicitly, if we take the monzo |e2 e3 ... ep&gt; then the Tenney-Euclidean norm, or TE norm, of it is<br /> | Because of the mathematical advantages of Euclidean norms, a Euclidean norm is often placed on the vectors in interval space instead of an L1 norm, in which case we have <a class="wiki_link" href="/Tenney-Euclidean%20metrics">Tenney-Euclidean interval space</a> instead of Tenney interval space. Explicitly, if we take the monzo |e2 e3 ... ep&gt; then the Tenney-Euclidean norm, or TE norm, of it is<br /> | ||
Revision as of 02:48, 4 March 2012
IMPORTED REVISION FROM WIKISPACES
This is an imported revision from Wikispaces. The revision metadata is included below for reference:
- This revision was by author genewardsmith and made on 2012-03-04 02:48:05 UTC.
- The original revision id was 307514102.
- The revision comment was:
The revision contents are below, presented both in the original Wikispaces Wikitext format, and in HTML exactly as Wikispaces rendered it.
Original Wikitext content:
A [[Harmonic Limit|p-limit]] rational number q can by definition be factored into primes of size less than or equal to p, giving
[[math]]
q = 2^{e_2} \, 3^{e_3} \, 5^{e_5} \dotso p^{e_p}
[[math]]
where the exponents are integers (positive, negative, or zero.) This is often written in [[http://mathworld.wolfram.com/Ket.html|ket vector]] ([[http://en.wikipedia.org/wiki/Bra-ket_notation|wp]]) notation as
[[math]]
|e_2 \, e_3 \, e_5 \dotso e_p\rangle
[[math]]
in which case it is called a **monzo**, where the name refers to the enthusiastic advocacy of [[Joe Monzo]].
The [[Tenney Height|Tenney height]] of this monzo is given by
[[math]]
\| |e_2 \, e_3 \dotso e_p \rangle \| = |e_2| + |e_3| \log_2 3 + \dotsb + |e_p| \log_2 p
[[math]]
which is a [[http://en.wikipedia.org/wiki/Normed_vector_space|vector space norm]]; hence we may [[http://en.wikipedia.org/wiki/Embedding|embed]] the p-limit monzos into a normed vector I space of dimension n = pi(p) via a map M:monzos -> I. The monzos under this embedding now define a [[http://en.wikipedia.org/wiki/Lattice_%28group%29|lattice]], which is a discrete subgroup spanning the finite dimensional real normed vector space I. If we change coordinates by multiplying values in the coordinate belonging to the prime k by log2(k), then the norm becomes the standard [[http://mathworld.wolfram.com/L1-Norm.html|L1 norm]]. This vector space is Tenney interval space, and the transformed coordinates with the standard L1 norm form the standard basis for Tenney space. It should be noted that while monzos correspond uniquely to positive real numbers (always rational numbers in the case of monzos), vectors in Tenney space do not. For instance, while |1 0> represents 2, so does |0 log3(2)>.
Because of the mathematical advantages of Euclidean norms, a Euclidean norm is often placed on the vectors in interval space instead of an L1 norm, in which case we have [[Tenney-Euclidean metrics|Tenney-Euclidean interval space]] instead of Tenney interval space. Explicitly, if we take the monzo |e2 e3 ... ep> then the Tenney-Euclidean norm, or TE norm, of it is
[[math]]
\sqrt{e_2^2 + (e_3\log_2 3)^2 + \dotsb + (e_p\log_2 p)^2}
[[math]]
and if the coordinates are the weighted interval space coordinates, then the TE norm is the [[http://mathworld.wolfram.com/L2-Norm.html|standard Euclidean, or L2, norm]].
==Example==
The 5-limit interval 16/15 factors as 2^4 3^(-1) 5^(-1), so it has a monzo representation of |4 -1 -1>. In weighted coordinates, that becomes |4 -log2(3) -log2(5)>, approximately |4 -1.585 -2.322>. The TE norm is therefore √(1^2 + log2(3)^2 + log2(5)^2) ≅ √23.903 ≅ 4.889.
//see also [[Fractional monzos]], [[Vals and Tuning Space]]...//Original HTML content:
<html><head><title>Monzos and Interval Space</title></head><body>A <a class="wiki_link" href="/Harmonic%20Limit">p-limit</a> rational number q can by definition be factored into primes of size less than or equal to p, giving<br />
<!-- ws:start:WikiTextMathRule:0:
[[math]]<br/>
q = 2^{e_2} \, 3^{e_3} \, 5^{e_5} \dotso p^{e_p}<br/>[[math]]
--><script type="math/tex">q = 2^{e_2} \, 3^{e_3} \, 5^{e_5} \dotso p^{e_p}</script><!-- ws:end:WikiTextMathRule:0 --><br />
where the exponents are integers (positive, negative, or zero.) This is often written in <a class="wiki_link_ext" href="http://mathworld.wolfram.com/Ket.html" rel="nofollow">ket vector</a> (<a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Bra-ket_notation" rel="nofollow">wp</a>) notation as<br />
<!-- ws:start:WikiTextMathRule:1:
[[math]]<br/>
|e_2 \, e_3 \, e_5 \dotso e_p\rangle<br/>[[math]]
--><script type="math/tex">|e_2 \, e_3 \, e_5 \dotso e_p\rangle</script><!-- ws:end:WikiTextMathRule:1 --><br />
in which case it is called a <strong>monzo</strong>, where the name refers to the enthusiastic advocacy of <a class="wiki_link" href="/Joe%20Monzo">Joe Monzo</a>.<br />
<br />
The <a class="wiki_link" href="/Tenney%20Height">Tenney height</a> of this monzo is given by<br />
<!-- ws:start:WikiTextMathRule:2:
[[math]]<br/>
\| |e_2 \, e_3 \dotso e_p \rangle \| = |e_2| + |e_3| \log_2 3 + \dotsb + |e_p| \log_2 p<br/>[[math]]
--><script type="math/tex">\| |e_2 \, e_3 \dotso e_p \rangle \| = |e_2| + |e_3| \log_2 3 + \dotsb + |e_p| \log_2 p</script><!-- ws:end:WikiTextMathRule:2 --><br />
<br />
which is a <a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Normed_vector_space" rel="nofollow">vector space norm</a>; hence we may <a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Embedding" rel="nofollow">embed</a> the p-limit monzos into a normed vector I space of dimension n = pi(p) via a map M:monzos -> I. The monzos under this embedding now define a <a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Lattice_%28group%29" rel="nofollow">lattice</a>, which is a discrete subgroup spanning the finite dimensional real normed vector space I. If we change coordinates by multiplying values in the coordinate belonging to the prime k by log2(k), then the norm becomes the standard <a class="wiki_link_ext" href="http://mathworld.wolfram.com/L1-Norm.html" rel="nofollow">L1 norm</a>. This vector space is Tenney interval space, and the transformed coordinates with the standard L1 norm form the standard basis for Tenney space. It should be noted that while monzos correspond uniquely to positive real numbers (always rational numbers in the case of monzos), vectors in Tenney space do not. For instance, while |1 0> represents 2, so does |0 log3(2)>.<br />
<br />
Because of the mathematical advantages of Euclidean norms, a Euclidean norm is often placed on the vectors in interval space instead of an L1 norm, in which case we have <a class="wiki_link" href="/Tenney-Euclidean%20metrics">Tenney-Euclidean interval space</a> instead of Tenney interval space. Explicitly, if we take the monzo |e2 e3 ... ep> then the Tenney-Euclidean norm, or TE norm, of it is<br />
<!-- ws:start:WikiTextMathRule:3:
[[math]]<br/>
\sqrt{e_2^2 + (e_3\log_2 3)^2 + \dotsb + (e_p\log_2 p)^2}<br/>[[math]]
--><script type="math/tex">\sqrt{e_2^2 + (e_3\log_2 3)^2 + \dotsb + (e_p\log_2 p)^2}</script><!-- ws:end:WikiTextMathRule:3 --><br />
and if the coordinates are the weighted interval space coordinates, then the TE norm is the <a class="wiki_link_ext" href="http://mathworld.wolfram.com/L2-Norm.html" rel="nofollow">standard Euclidean, or L2, norm</a>.<br />
<br />
<!-- ws:start:WikiTextHeadingRule:4:<h2> --><h2 id="toc0"><a name="x-Example"></a><!-- ws:end:WikiTextHeadingRule:4 -->Example</h2>
The 5-limit interval 16/15 factors as 2^4 3^(-1) 5^(-1), so it has a monzo representation of |4 -1 -1>. In weighted coordinates, that becomes |4 -log2(3) -log2(5)>, approximately |4 -1.585 -2.322>. The TE norm is therefore √(1^2 + log2(3)^2 + log2(5)^2) ≅ √23.903 ≅ 4.889.<br />
<br />
<em>see also <a class="wiki_link" href="/Fractional%20monzos">Fractional monzos</a>, <a class="wiki_link" href="/Vals%20and%20Tuning%20Space">Vals and Tuning Space</a>...</em></body></html>