20151220 memory
20 Dec 20152015 年 12 月 20 日上午 10 点到 11 点，对我的人生来说很重要，谢谢你。
In the lecture Corporate Finance, Teaching Assistant Jessie Wang provides an excellent note.
Let’s Encrypt is an awesome project providing free SSL certs to the world. In Dec 3, 2015, it entered public beta.
Do NOT need to read this post. Please checkout the updated post for a better solution and a better explanation.
Mathematica is a great solution to some computing problems. However it has only one disadvantage: it is very expensive. Any other way to avoid the fee? No, I am not talking about swithching to R, Python, etc.
I began learning English at age of 10 in primary school. However, it is in 2005 that I fell in love with English and realized its importance in my life.
Dual Thrust is a very simple but seemly effective strategy in quantitative investment.
最近想试一下捣腾一个 R 包出来，故参考了一些教程。现在看到的最好的就是谢益辉大大之前写过的开发R程序包之忍者篇，以及 Hadley 大神（ggplot2 devtools 等一系列包的作者）的 教程。但是前者有一些过时，后者是全英文的，所以我这里记录一下比较简单的过程，给读者们一个参考思路。如果你有一些 R 程序，想塞到去一个自创的 R 包中，那么这篇文章就可能是你想要的。为了方便说明，这里用我的包来进行示例。