<link rel="shortcut icon" type="image/jpg" href="/favicon.jpeg"/>

<?xml version="1.0"?>
<feed xmlns="http://www.w3.org/2005/Atom" xml:lang="en">
	<id>http://64.23.165.198:80/index.php?action=history&amp;feed=atom&amp;title=Coordinates</id>
	<title>Coordinates - Revision history</title>
	<link rel="self" type="application/atom+xml" href="http://64.23.165.198:80/index.php?action=history&amp;feed=atom&amp;title=Coordinates"/>
	<link rel="alternate" type="text/html" href="http://64.23.165.198:80/index.php?title=Coordinates&amp;action=history"/>
	<updated>2026-04-17T12:55:43Z</updated>
	<subtitle>Revision history for this page on the wiki</subtitle>
	<generator>MediaWiki 1.41.0</generator>
	<entry>
		<id>http://64.23.165.198:80/index.php?title=Coordinates&amp;diff=356&amp;oldid=prev</id>
		<title>Lfox at 19:59, 28 February 2024</title>
		<link rel="alternate" type="text/html" href="http://64.23.165.198:80/index.php?title=Coordinates&amp;diff=356&amp;oldid=prev"/>
		<updated>2024-02-28T19:59:22Z</updated>

		<summary type="html">&lt;p&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 19:59, 28 February 2024&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l1&quot;&gt;Line 1:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 1:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;A &#039;&#039;&#039;coordinate system&#039;&#039;&#039; is a system assigning a number (or [[Set|tuple]] of numbers) to &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;every &lt;/del&gt;[[point]] &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;on &lt;/del&gt;an [[entity]]. The number (or tuple of numbers) assigned to a point is called the &#039;&#039;&#039;coordinate&#039;&#039;&#039; (or &#039;&#039;&#039;coordinates&#039;&#039;&#039;) of the point.  &lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;A &#039;&#039;&#039;coordinate system&#039;&#039;&#039; is a system assigning a number (or [[Set|tuple]] of numbers) to &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;any &lt;/ins&gt;[[point]] &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;lying in a subregion of &lt;/ins&gt;an [[entity]]. The number (or tuple of numbers) assigned to a point is called the &#039;&#039;&#039;coordinate&#039;&#039;&#039; (or &#039;&#039;&#039;coordinates&#039;&#039;&#039;) of the point.  &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt; &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;An atlas is a set of coordinate systems, such that their corresponding subregions cover the entity.  &lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== Examples ==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== Examples ==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l7&quot;&gt;Line 7:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 9:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Using a similar procedure, if one picks a [[ray]] on a plane, one can use it to define a &amp;quot;polar&amp;quot; coordinate system on the plane.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Using a similar procedure, if one picks a [[ray]] on a plane, one can use it to define a &amp;quot;polar&amp;quot; coordinate system on the plane.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;== Entity vs. Manifold ==&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[TODO]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Lfox</name></author>
	</entry>
	<entry>
		<id>http://64.23.165.198:80/index.php?title=Coordinates&amp;diff=343&amp;oldid=prev</id>
		<title>Lfox: /* Examples */</title>
		<link rel="alternate" type="text/html" href="http://64.23.165.198:80/index.php?title=Coordinates&amp;diff=343&amp;oldid=prev"/>
		<updated>2024-02-14T04:25:43Z</updated>

		<summary type="html">&lt;p&gt;&lt;span dir=&quot;auto&quot;&gt;&lt;span class=&quot;autocomment&quot;&gt;Examples&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 04:25, 14 February 2024&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l4&quot;&gt;Line 4:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 4:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Longitude and latitude are a coordinate system for the surface of the earth.  &lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Longitude and latitude are a coordinate system for the surface of the earth.  &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;If one picks two lines on a [[Surface#Plane|plane]] which meet at right angles, then one &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;has implicitly chosen &lt;/del&gt;a &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Cartesian &lt;/del&gt;coordinate system for the plane.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;If one picks two &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[oriented]] &lt;/ins&gt;lines on a [[Surface#Plane|plane]] which meet at right angles, then one &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;can use them to define &lt;/ins&gt;a coordinate system for &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;the plane, called &quot;cartesian&quot; coordinates. The cartesian coordinates of a point &amp;lt;math&amp;gt;p&amp;lt;/math&amp;gt; on the plane are two numbers &amp;lt;math&amp;gt;(x_p, y_p)&amp;lt;/math&amp;gt;, determined as follows. First, [[order]] the two lines using the right-hand rule: the [[cross product]] of the first line with second line should point away from you. Project &amp;lt;math&amp;gt;p&amp;lt;/math&amp;gt; onto the first line, and let &amp;lt;math&amp;gt;x_p&amp;lt;/math&amp;gt; denote the (signed) distance between its projection and the origin. Similarly, project &amp;lt;math&amp;gt;p&amp;lt;/math&amp;gt; onto the second line, and let &amp;lt;math&amp;gt;y_p&amp;lt;/math&amp;gt; denote the (signed) distance between its projection and the origin. &lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt; &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Using a similar procedure, if one picks a [[ray]] on a plane, one can use it to define a &quot;polar&quot; coordinate system on &lt;/ins&gt;the plane.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Lfox</name></author>
	</entry>
	<entry>
		<id>http://64.23.165.198:80/index.php?title=Coordinates&amp;diff=342&amp;oldid=prev</id>
		<title>Lfox: Created page with &quot;A &#039;&#039;&#039;coordinate system&#039;&#039;&#039; is a system assigning a number (or tuple of numbers) to every point on an entity. The number (or tuple of numbers) assigned to a point is called the &#039;&#039;&#039;coordinate&#039;&#039;&#039; (or &#039;&#039;&#039;coordinates&#039;&#039;&#039;) of the point.   == Examples == Longitude and latitude are a coordinate system for the surface of the earth.   If one picks two lines on a plane which meet at right angles, then one has implicitly chosen a Cartesian coordinate...&quot;</title>
		<link rel="alternate" type="text/html" href="http://64.23.165.198:80/index.php?title=Coordinates&amp;diff=342&amp;oldid=prev"/>
		<updated>2024-02-14T04:12:18Z</updated>

		<summary type="html">&lt;p&gt;Created page with &amp;quot;A &amp;#039;&amp;#039;&amp;#039;coordinate system&amp;#039;&amp;#039;&amp;#039; is a system assigning a number (or &lt;a href=&quot;/index.php/Set&quot; title=&quot;Set&quot;&gt;tuple&lt;/a&gt; of numbers) to every &lt;a href=&quot;/index.php/Point&quot; title=&quot;Point&quot;&gt;point&lt;/a&gt; on an &lt;a href=&quot;/index.php/Entity&quot; title=&quot;Entity&quot;&gt;entity&lt;/a&gt;. The number (or tuple of numbers) assigned to a point is called the &amp;#039;&amp;#039;&amp;#039;coordinate&amp;#039;&amp;#039;&amp;#039; (or &amp;#039;&amp;#039;&amp;#039;coordinates&amp;#039;&amp;#039;&amp;#039;) of the point.   == Examples == Longitude and latitude are a coordinate system for the surface of the earth.   If one picks two lines on a &lt;a href=&quot;/index.php/Surface#Plane&quot; title=&quot;Surface&quot;&gt;plane&lt;/a&gt; which meet at right angles, then one has implicitly chosen a Cartesian coordinate...&amp;quot;&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;A &amp;#039;&amp;#039;&amp;#039;coordinate system&amp;#039;&amp;#039;&amp;#039; is a system assigning a number (or [[Set|tuple]] of numbers) to every [[point]] on an [[entity]]. The number (or tuple of numbers) assigned to a point is called the &amp;#039;&amp;#039;&amp;#039;coordinate&amp;#039;&amp;#039;&amp;#039; (or &amp;#039;&amp;#039;&amp;#039;coordinates&amp;#039;&amp;#039;&amp;#039;) of the point. &lt;br /&gt;
&lt;br /&gt;
== Examples ==&lt;br /&gt;
Longitude and latitude are a coordinate system for the surface of the earth. &lt;br /&gt;
&lt;br /&gt;
If one picks two lines on a [[Surface#Plane|plane]] which meet at right angles, then one has implicitly chosen a Cartesian coordinate system for the plane.&lt;/div&gt;</summary>
		<author><name>Lfox</name></author>
	</entry>
</feed>