Cartesian scale: Difference between revisions

<h2>IMPORTED REVISION FROM WIKISPACES</h2>

This is an imported revision from Wikispaces. The revision metadata is included below for reference:<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>

If the generators are odd primes and ℇ = 2, then the Cartesian scale is an [[Euler genera|Euler genus]]; if G = [p1,  p2 ... pk] are the generators and M = [m1, m2 .. mk] the multiplicities, then Genus(p1^m1 p2^m2 ... pk^mk) = Descartes(2, G, M). By the [[http://en.wikipedia.org/wiki/Fundamental_theorem_of_arithmetic|fundamental theorem of arithmetic]], the odd prime generators define an [[http://en.wikipedia.org/wiki/Integer_lattice|integer lattice]], the points of which define unique representatives of the pitch classes of the scale. These ℇ-equivalence pitch classes form a [[http://en.wikipedia.org/wiki/Convex_lattice_polytope|Z-polytope]] which consists of the set of lattice points contained in an [[http://en.wikipedia.org/wiki/Hyperrectangle|orthotope]] aligned with the lattice. The same is true more generally for any [[http://planetmath.org/multiplicativelyindependent|multiplicatively independent]] set {ℇ}∪G of generators; a Cartesian scale defined in terms of these may be called "independent". On the other hand if we expand the scale by increasing each of the multiplicities by one, and if in this expanded scale there are two notes on distinct lattice points with the same numerical value, we may call the scale "dependent".

If the generators are odd primes and ℇ = 2, then the Cartesian scale is an &lt;a class="wiki_link" href="/Euler%20genera"&gt;Euler genus&lt;/a&gt;; if G = [p1,  p2 ... pk] are the generators and M = [m1, m2 .. mk] the multiplicities, then Genus(p1^m1 p2^m2 ... pk^mk) = Descartes(2, G, M). By the &lt;a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Fundamental_theorem_of_arithmetic" rel="nofollow"&gt;fundamental theorem of arithmetic&lt;/a&gt;, the odd prime generators define an &lt;a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Integer_lattice" rel="nofollow"&gt;integer lattice&lt;/a&gt;, the points of which define unique representatives of the pitch classes of the scale. These ℇ-equivalence pitch classes form a &lt;a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Convex_lattice_polytope" rel="nofollow"&gt;Z-polytope&lt;/a&gt; which consists of the set of lattice points contained in an &lt;a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Hyperrectangle" rel="nofollow"&gt;orthotope&lt;/a&gt; aligned with the lattice. The same is true more generally for any &lt;a class="wiki_link_ext" href="http://planetmath.org/multiplicativelyindependent" rel="nofollow"&gt;multiplicatively independent&lt;/a&gt; set {ℇ}∪G of generators; a Cartesian scale defined in terms of these may be called &amp;quot;independent&amp;quot;. On the other hand if we expand the scale by increasing each of the multiplicities by one, and if in this expanded scale there are two notes on distinct lattice points with the same numerical value, we may call the scale &amp;quot;dependent&amp;quot;.&lt;br /&gt;

&lt;br /&gt;

&lt;br /&gt;

&lt;br /&gt;