K-means clustering and Bisecting K-means in Plain English
K-means clustering is unsupervised machine learning algorithm. Wikipedia has a great demo as below on how it works: Demonstration of the standard algorithm 1. k initial “means” (in this case…
When/where C++ five constructors (copy/assignment/mmove) are invoked
C++ default , copy, move, assignment constructors Sometimes it is confusing where/when the default , copy, move, assignment constructors in C++ are invoked, here some are notes: e.g.: class A…
Bison/Yacc cheat sheet ( Parser Generator cheat sheet)
The same thing happened to bison/yacc, I googled around, and was a little surprised that I could not find a bison/yacc cheat sheet. So I made a very rudimentary one here. Bison-Yacc_cheat_sheet…
Flex cheat sheet (The Fast Lexical Analyzer cheat sheet)
I googled around, and was a little surprised that I could not find a flex/flex cheat sheet. So I made a very rudimentary one here. flex_cheat_sheet Please comment on how to improve…
SVM ( support vecotr machine) in Plain English
(1) Maximum the margin SVM is very easy to understand on the graph,, we just need to find the a separate plane which maximum the margin. see the graph below: (2)…
Quadratic programming in plain English
The big picture is: a quadratic programming problem can be reduced to be a linear programming problem. Here is how: (1) KTT conditions For any non-linear programming: max: f(x), s.t: g(x)…
socat introduction
While searching a command line to write something into a UNIX Domain Socket, I found this great tool called socat which is similar to netcat/samplicator but has more features. The…
Linear programming in plain English
Why study the linear programming (LP) ? LP has a lot of use cases, one of them is the SVM ( support vector machine). The SVM ‘s Lagrangian dual can give…
GDB cheatsheat
GDB cheatsheat There is a good gdb cheatsheet at http://darkdust.net/files/GDB%20Cheat%20Sheet.pdf The output format for print, x is missing there, somehow I think it is useful to add the output formats: x,d,u,o,t,a,f,s,z,r…
人生最曼妙的风景，竟是内心的淡定与从容
有人说《一百岁感言》并非杨绛先生本人所作, 咱们中国的网络真的是真假难辩，难道这也需要方舟子打假？ 不管怎样，出于敬重缅怀, 摘录此文以之怀念杨绛先生 杨绛： 我今年一百岁，已经走到了人生的边缘，我无法确知自己还能走多远，寿命是不由自主的，但我很清楚我快“回家”了。 我得洗净这一百年沾染的污秽回家。 我没有“登泰山而小天下”之感，只在自己的小天地里过平静的生活。细想至此，我心静如水，我该平和地迎接每一天，准备回家。 在这物欲横流的人世间，人生一世实在是够苦。你存心做一个与世无争的老实人吧，人家就利用你欺侮你。你稍有才德品貌，人家就嫉妒你排挤你。 你大度退让，人家就侵犯你损害你。你要不与人争，就得与世无求，同时还要维持实力准备斗争。你要和别人和平共处，就先得和他们周旋，还得准备随时吃亏。 少年贪玩，青年迷恋爱情，壮年汲汲于成名成家，暮年自安于自欺欺人。 人寿几何，顽铁能炼成的精金，能有多少？但不同程度的锻炼，必有不同程度的成绩；不同程度的纵欲放肆，必积下不同程度的顽劣。 上苍不会让所有幸福集中到某个人身上，得到爱情未必拥有金钱；拥有金钱未必得到快乐；得到快乐未必拥有健康；拥有健康未必一切都会如愿以偿。 保持知足常乐的心态才是淬炼心智，净化心灵的最佳途径。一切快乐的享受都属于精神，这种快乐把忍受变为享受，是精神对于物质的胜利，这便是人生哲学。 一个人经过不同程度的锻炼，就获得不同程度的修养、不同程度的效益。好比香料，捣得愈碎，磨得愈细，香得愈浓烈。我们曾如此渴望命运的波澜，到最后才发现：人生最曼妙的风景，竟是内心的淡定与从容……我们曾如此期盼外界的认可，到最后才知道：世界是自己的，与他人毫无关系。 References: http://news.wenweipo.com/2016/05/25/IN1605250061.htm http://newspaper.jfdaily.com/xwcb/files/20130718/322242.PDF http://zj.zjol.com.cn/news/350115.html
