<?xml version="1.0" encoding="UTF-8"?><rss xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:atom="http://www.w3.org/2005/Atom" version="2.0"><channel><title><![CDATA[RSS Feed]]></title><description><![CDATA[RSS Feed]]></description><link>http://direct.ecency.com</link><image><url>http://direct.ecency.com/logo512.png</url><title>RSS Feed</title><link>http://direct.ecency.com</link></image><generator>RSS for Node</generator><lastBuildDate>Wed, 22 Apr 2026 18:49:46 GMT</lastBuildDate><atom:link href="http://direct.ecency.com/@jifka/rss" rel="self" type="application/rss+xml"/><item><title><![CDATA[Simplefootball - The idea]]></title><description><![CDATA[In my introduction I said that I would also present some of my programming and today we will get started with that. The program I want to talk about is a simple football (soccer) simulation that I have]]></description><link>http://direct.ecency.com/programming/@jifka/simplefootball-the-idea</link><guid isPermaLink="true">http://direct.ecency.com/programming/@jifka/simplefootball-the-idea</guid><category><![CDATA[programming]]></category><dc:creator><![CDATA[jifka]]></dc:creator><pubDate>Thu, 21 Feb 2019 16:47:36 GMT</pubDate><enclosure url="https://images.ecency.com/p/2FFvzA2zeqoVJ2SVhDmmumdPfnVEcahMce9nMwwksSDdRvUyU4WaWLMLqHd1gwwE9rN1LdKvhpkVKHvidKDvXHY5XrBqF8T7YeQaUwuHNXSPW91uiwdoKqWJdBWxE?format=match&amp;mode=fit" length="0" type="false"/></item><item><title><![CDATA[Polar coordinates]]></title><description><![CDATA[Today we will come back to complex numbers. As discussed before, a complex number z is represented as a + b * i with a and b real numbers and i the imaginary unit (the square root of -1). Since this is]]></description><link>http://direct.ecency.com/math/@jifka/polar-coordinates</link><guid isPermaLink="true">http://direct.ecency.com/math/@jifka/polar-coordinates</guid><category><![CDATA[math]]></category><dc:creator><![CDATA[jifka]]></dc:creator><pubDate>Fri, 25 Jan 2019 17:11:48 GMT</pubDate><enclosure url="https://images.ecency.com/p/cyxkEVqiiLy2ofdgrJNxeZC3WCHPBwR7MjUDzY4kBNr81Lf4iuujfA27ZGD3S8gyCZMyRKVLsp1K1ARQFhaE2uo5xDdWyHiC2fDibCNsdWHLt3EBaujaUNqFqr8cCU5J7G2?format=match&amp;mode=fit" length="0" type="false"/></item><item><title><![CDATA[The harmonic mean]]></title><description><![CDATA[Last time we looked at the geometric mean in contrast to the “normal” arithmetic mean. There is even a third way to determine the “middle” of two numbers, the harmonic mean. The harmonic mean of two numbers]]></description><link>http://direct.ecency.com/math/@jifka/the-harnonic-mean</link><guid isPermaLink="true">http://direct.ecency.com/math/@jifka/the-harnonic-mean</guid><category><![CDATA[math]]></category><dc:creator><![CDATA[jifka]]></dc:creator><pubDate>Fri, 04 Jan 2019 14:58:09 GMT</pubDate></item><item><title><![CDATA[The geometric mean]]></title><description><![CDATA[When there is a competition to estimate some number (e.g. the amount of money in a jar full of coins) we want the person closest to the actual value to win. Since the distance between two numbers x and]]></description><link>http://direct.ecency.com/math/@jifka/the-geometric-mean</link><guid isPermaLink="true">http://direct.ecency.com/math/@jifka/the-geometric-mean</guid><category><![CDATA[math]]></category><dc:creator><![CDATA[jifka]]></dc:creator><pubDate>Thu, 27 Dec 2018 18:10:27 GMT</pubDate></item><item><title><![CDATA[Complex numbers]]></title><description><![CDATA[Some of my following posts might use complex numbers so I want to properly introduce them. To understand why we need them we will first take a look at other, more simple, sets of numbers. In elementary]]></description><link>http://direct.ecency.com/math/@jifka/complex-numbers</link><guid isPermaLink="true">http://direct.ecency.com/math/@jifka/complex-numbers</guid><category><![CDATA[math]]></category><dc:creator><![CDATA[jifka]]></dc:creator><pubDate>Sun, 16 Dec 2018 18:39:33 GMT</pubDate></item><item><title><![CDATA[Postfix notation]]></title><description><![CDATA[Most people don't think about how to write sums. It is clear that that the plus sign should go between the two numbers you want to add. This makes a lot of sense but when you think about it there is no]]></description><link>http://direct.ecency.com/math/@jifka/postfix-notation</link><guid isPermaLink="true">http://direct.ecency.com/math/@jifka/postfix-notation</guid><category><![CDATA[math]]></category><dc:creator><![CDATA[jifka]]></dc:creator><pubDate>Sun, 09 Dec 2018 16:58:48 GMT</pubDate></item><item><title><![CDATA[What is the minimum of an empty set?]]></title><description><![CDATA[The question what the smallest number in an empty set is might seem like nonsense because, you know, the set does not contain any numbers but this is just the kind of thing mathematicians worry about.]]></description><link>http://direct.ecency.com/math/@jifka/what-is-the-minimum-of-an-empty-set</link><guid isPermaLink="true">http://direct.ecency.com/math/@jifka/what-is-the-minimum-of-an-empty-set</guid><category><![CDATA[math]]></category><dc:creator><![CDATA[jifka]]></dc:creator><pubDate>Mon, 26 Nov 2018 20:41:09 GMT</pubDate></item><item><title><![CDATA[Why 0! = 1]]></title><description><![CDATA[Most of you should be familiar with the factorial function where n factorial (written n!) is the product of the first n natural numbers, e.g. 5! = 1 * 2 * 3 * 4 * 5 = 120. This is a straightforward definition]]></description><link>http://direct.ecency.com/math/@jifka/why-0-1</link><guid isPermaLink="true">http://direct.ecency.com/math/@jifka/why-0-1</guid><category><![CDATA[math]]></category><dc:creator><![CDATA[jifka]]></dc:creator><pubDate>Sun, 18 Nov 2018 20:47:09 GMT</pubDate></item><item><title><![CDATA[Introducing my maths blog]]></title><description><![CDATA[Hello there! I am currently studying maths at university and I made this account to share some of the interesting things I learn there (or anywhere else) as well as maybe some of my programming (maths-related]]></description><link>http://direct.ecency.com/introduceyourself/@jifka/introducing-my-maths-blog</link><guid isPermaLink="true">http://direct.ecency.com/introduceyourself/@jifka/introducing-my-maths-blog</guid><category><![CDATA[introduceyourself]]></category><dc:creator><![CDATA[jifka]]></dc:creator><pubDate>Sun, 18 Nov 2018 20:19:27 GMT</pubDate></item></channel></rss>