Chun-Hung Tseng henrybear327

Concurrency Patterns in Go

Notes taken from Rob Pike's presentation 'Google I/O 2012 - Go Concurrency Patterns'.

1. Generator: function that returns a channel

The code is as follows:

c := boring("boring!")  // function returning a channel

for i := 0; i &lt; 5; i++ {

進修計劃書

在大學期間的選修課程選擇，令我廣泛的接觸了多個不同的資訊研究領域。在這其中，我對於電腦視覺與圖形識別的發展特別有興趣，接下來也打算朝著這個方面進行探索，期許自己可以在進入研究所前，有更明確的研究方向。

短程- 進入研究所前

在取得入學許可之後，會盡速與相關實驗室進行聯絡，尋求意見與協助，以利未來入學做準備。並且複習電腦科學的基本課程，重新溫習一些重要的概念，不忘記基本的準則，為此後的研究進行準備。準備複習的內容為下表：

線性代數
離散數學

Pretty print bookmarklet helper for Gist pages

Create a new bookmark somewhere handy in your browser with the following URL:

javascript:var el=document.createElement('style');el.media='print';el.innerHTML='#header,.pagehead.repohead,.gist-description.container,.file-box .meta,#comments,.js-comment-form,#footer{display:none;}.file-box{border:0!important;}';document.getElementsByTagName('head')[0].appendChild(el);alert('Please consider the environment before printing :)');

Navigate to your Gist of choice
Hit the bookmarklet
Now print

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

RTAI installation for ubuntu 14.04

Preparation

Switch user mode

sudo su

download and unzip

Launch Sublime Text 2 from the Mac OS X Terminal

Sublime Text 2 ships with a CLI called subl (why not "sublime", go figure). This utility is hidden in the following folder (assuming you installed Sublime in /Applications like normal folk. If this following line opens Sublime Text for you, then bingo, you're ready.

open /Applications/Sublime\ Text\ 2.app/Contents/SharedSupport/bin/subl

You can find more (official) details about subl here: http://www.sublimetext.com/docs/2/osx_command_line.html

	// assumes you add a timestamp field to each record (see Firebase.ServerValue.TIMESTAMP)
	// pros: fast and done server-side (less bandwidth, faster response), simple
	// cons: a few bytes on each record for the timestamp
	var ref = new Firebase(...);
	ref.orderByChild('timestamp').startAt(Date.now()).on('child_added', function(snapshot) {
	console.log('new record', snap.key());
	});

	/*
	使用前调用init静态建树，然后模仿query进行类Binary Search Tree式的访问即可
	Obj是点的类型，如果追求效率或者在点上除了坐标还有其它信息，可以自己写一个Obj类，然后重载[]运算符
	*/
	namespace KDTree {
	int K;
	typedef vector <int> Obj;
	template <int T> bool cmpT(const Obj &a, const Obj &b) { return a[T] < b[T]; }
	bool (*cmp[])(const Obj &, const Obj &) = {cmpT <0>, cmpT <1>, cmpT <2>}; //填到所需要的最大维度数目为止，这里表示的是最大3维
	struct Filter {

	def lowerBound(a, key)
	lb = -1; ub = a.length
	while ub - lb > 1
	mid = (lb + ub) / 2
	if a[mid] >= key
	ub = mid
	else
	lb = mid
	end
	end

	/*
	Infix to postfix conversion in C++
	Input Postfix expression must be in a desired format.
	Operands and operator, both must be single character.
	Only '+' , '-' , '*', '/' and '$' (for exponentiation) operators are expected.
	*/
	#include<iostream>
	#include<stack>
	#include<string>