用iPhone 做 GPS Logger 及 Geotag 相片

上星期和朋友挑戰體能極限，由東涌騎單車入廸欣湖。因為路程不是傳統的單車徑，也沒有指示牌，所以忽發奇想，想寫一篇攻略，方便想挑戰這條路的大小朋友。

為了完成這個偉大，找來了一個不錯用的iPhone app，叫做 Geotag Photo Pro。
官方網址：http://www.geotagphotos.net/en/
AppStore 網址：http://itunes.apple.com/us/app/geotag-photos-pro/id355503746?mt=8
GPS Logging
要做GPS Log 的做法十分簡單，首先從AppStore 買下這個app，然後把它打開，以下是它的主畫面：

第一次先用按New trip，然後輸入一個行程名稱。

完成後返回主畫面，你可以先進入Autolog選項

在這裡你可以選擇每隔多少分鐘記下GPS位置，上次騎單車我選了兩分鐘，但發現騎單車有時騎得快，結果記下來的不太準確。但注意如果調得太密，電量消耗會很大。(給大家作參考，我用的是3GS，再外接一顆MiPOW Power Tube 2200，有2200mAh 的後備電量，由早上十一時多到晚上八時多都沒大問題。)

再進入第二項 Settings & Upload

這裡有很多不同的設定，先看看Accuracy settings

第一項設定的也不知道，如果有朋友知道的請告訴我。第二項設定比較有用，預設它只會用GPS作為記錄的訊號，但如果身處室內，我建議還是設定為GPS+GSM，那定位會比較準確。

Notifications、Advanced Settings 和 Setup time on camera， 只是一些基本設定，這裡就略過不提了。Upload logged data 只是將你的GPS LOG 上載到官網那裡做Geotag，但由於官網有提供免費的offline Geotag 工具，所以這個選項也略過不提。
所有設定都完成了，那可以開始記錄行程了！先回主畫面，然後按REC ，那麼旅程就會開始記錄了。緊記旅程完結後也要停止記錄，不然你把你回家的路程也記錄了。

Geotagg 相片
要Geotag 相片，方法也很簡單，首是先進入 Settings & Upload ，然後進入 Link with Geotagphotos.net ，點選這裡會帶你到官網申請賬戶。
申請賬戶後，到官網，點選右上角的Geotag your photos now，然後登入賬戶。

登入後在右手面你會發現一個Geotag 工具的offline version，先下載它。

這個軟體是一個JAVA 程式 (runGeotagPhotosOffline.jnlp)，所以你必需先安裝JAVA，如沒有裝請到這裡安裝：http://www.java.com/zh_TW/
安裝JAVA 後，打開軟體，它會問你要兩個東西：
1. GPX file
2. 要做Geotag 的相片所存放的位置

第二點對大家沒有難度，那第一點要如何那到GPX file 呢？方法也很簡單，先進入APP，然後選擇先前記錄好的LOG。

進入這個畫面後，選擇想滙出行程 (按右手面的藍色箭咀)。

然後選 Export to Email ，之後到自己的電郵下載GPX 檔。

下在完成後，在 Geotag 軟體選好剛下載的GPX 檔，然後等軟體載入相片，然後按下 Geotagging ，軟體就會為你每張上片加入位置資訊。

待所有相片處理完成後，你用一些支援定位的看圖軟件如 Picasa 打開相片，你就會看到相片的定位了！
謝謝收看！

[教學] 在 eclipse 裡設定 JQuantLib 的開發環境 (Setup JQuantLib in eclipse)

工作需要，這幾天都在研究一套JAVA 的Quantative finance library – JQuantLib。
因為暫時只是在POC階段，所以先寫安裝方法，不寫這套library 的內容。

我的開發環境：

• J2SE 1.5.0_22
• Eclipse Helio (service release 2)

在eclipse 的設定方法 (假設大家都懂得如可在eclipse 加入新插件)：

1. 安裝 Maven Integration for Eclipse
   Maven 與 Eclipse 的 integration
   Eclipse update url: http://download.eclipse.org/technology/m2e/releases
   
2. 安裝 Subversive
   打開 Help > Install New Software... > select Helios - http://download.eclipse.org/releases/helios > Collaboration Tools，安裝以下一堆plug-in
   
   安裝完成後會有對話框詢問你要裝甚麼connector，我沒有理會，通通都把它裝起來。
   
   
3. 安裝 FingBugs
   Description: Tools that analyse your code and point out the place that you may got a bug or have a bad practise.
   Eclipse update url: http://findbugs.cs.umd.edu/eclipse/
   
4. 安裝 PMD
   Description: Help to find bad constructions in the code, either those commonly known or those defined by JQuantLib.
   Eclipse update url: http://pmd.sf.net/eclipse
   
5. 安裝 EclEmma
   Description: Tools for easy verify of the code coverage of your JUnit test cases.
   Eclipse update url: http://update.eclemma.org/
   
6. 設定 JQuantLib SVN Repository
   
• Right click 有關的project，然後 New > Other，然後選SVN > Repository Location.
  
  
• 在URL輸入http://jquant.svn.sourceforge.net/svnroot/jquant/trunk/jquantlib，然後按Finish。
   
  
• 要加入的Repositories 有以下五個：
  http://jquant.svn.sourceforge.net/svnroot/jquant/trunk/jquantlib
  http://jquant.svn.sourceforge.net/svnroot/jquant/trunk/jquantlib-all
  http://jquant.svn.sourceforge.net/svnroot/jquant/trunk/jquantlib-parent
  http://jquant.svn.sourceforge.net/svnroot/jquant/trunk/jquantlib-helpers
  http://jquant.svn.sourceforge.net/svnroot/jquant/trunk/jquantlib-samples
  
  
  
7. Check out JQuantLib source
• 打開Window > Show View > Others，點選 SVN Repositories。
  
  
• 在SVN Repositories 的 view 入面，right click 剛新加入的repositories，然後選Find/Check Out As…。
  
  
• 然後選 Check out as a project with the name specified:，然後按Finish。
  
  
• Check out in progress ……
  
  
• 重覆以上步驟直到所有repositories 都check out 完成。
  
  
• 完成！

Reference:
http://www.jquantlib.org/index.php/JQuantLib_Users_Guide#Install_plugins
http://www.jquantlib.org/index.php/Checkout_in_Eclipse_with_SVN

Google+ & Facebook 同步發表 (sync post)

Google+的確是十分好用，但可惜的是暫尚未普及，所以暫時還不能放棄facebook。
今期 e-zone (676期) 送了一本Google+的小册子，其中有一個不錯用的Chrome extension ，可以將google+的帖子同時分享至facebook (or twitter)，所以在這裡轉貼一下。
Google+ & Facebook 同步發表拓展
https://chrome.google.com/webstore/detail/aamklbolfkledofgpbdllkangemkfdnb?hl=zh-TW

安裝方法：

1. 進入這個extension的主頁，在右下角選安裝
   
2. 安裝程序簡單，不用數秒就已完成，然後你會發現Chrome 和Google+的右上角分別多了一個icon。
   
3. 假如安裝時，你已經登入了facebook，你按ctrl + F5 重新整理你的頁面後，你會發現在分享信息是多了facebook 的選項。
   
4. 只要你選了facebook，那你發佈到Google+ 的信息就會同時發佈到facebook。
   
5. 設定方面你可以在chrome 按一下右上角的，就可以設定Google+ 和 facebook 賬戶的連結。
   

Reference: e-zone (676期) - Google+ 新手速食天書

Printing multiple word documents with duplex settings in windows XP

Here is the steps:

1. Open any one of the word document, the go to File –> Print.
2. Then set the printer properties you want, like print on both sides, pages per sheet, etc.
   
3. Print the first document as normal.
4. Then keep the first document open, don’t close it. Right click on the others file you want to print.
   On the menu, click on Print.
   
5. A new word window will pop up and disappear immediatly. The file will be printed with the printer setting of the 1st document.
6. Repeat step 4 for all other file you want to print. In this way, you don’t need to open the word document one by one and select the print function.

Enjoy!

PCCW 100M VDSL VS 100M Fiber Direct

光纖真係快好多，有圖有真相。

PCCW 100M 光纖

PCCW 100M VDSL

Use IE Tab on Chrome

因為毛毛公司要用到Outlook Web，自己維護的系統也要用到Internet Component Download，所以迫不得已要用IE。

要同時用IE和chrome很煩人，而且近期發現一個怪現象，就是我晚上log off 了windows 後，第二朝回來log in總總發現IE會吃掉我大部分系統資源，每天早上都要強迫我使出「ctrl + alt + del」大法……

這天早上「的起心肝」找找有沒有在chrome上用IE engine的方法，發現了一個很好用的extension：Chrome IE Tab Multi

https://chrome.google.com/webstore/detail/fnfnbeppfinmnjnjhedifcfllpcfgeea?hl=zh-TW

安裝後chrome 右上角會多了一個 IE 的icon：

每次你想在chrome開IE 的網頁，只要按一下這個icon，新開的tab 就會變成IE 的tab：

測試了Outlook web 和商台的網上直播都沒有問題，暫時我想我可以將IE 放在一旁了！

在XP 設定與天文台的Internet Time同步 (command line)

這兩天發現辦公室的電腦時間DELAY 了後多，經調查後懷疑公司DOMAIN SERVER 的時間有誤，所以希望把電腦時鐘和天文台的標準時間同步，一般電腦的設定如下：
http://www.hko.gov.hk/nts/Xp-syncc.htm
可是問題來了，由於公司電腦已經加入了domain，所以沒有「網際網絡時間」的選項……
幸好有Google 大神，原來可以透過command line 的方法來設定和天文台的時間同步，方法如下：

1. net time /setsntp:stdtime.gov.hk
2. net stop w32time
3. net start w32time
4. 等5-10分鐘左右，你會發現你的時間會自動和天文台同步了

Internet Component Download - INF File Architecture

Introduction

An information file (.inf) provide the installation instruction for IE to setup and register your software distribution. It consists of any number of name section. And each section can have multiple items.

Each section will have its own predefined purpose, such as updating the registry, executing a command, copying some file, etc.

Main Sections of an INF File in Internet Component Download:

• [Add.Code]
  This section lists all the files to be installed, including optional files

  [Add.Code]
  filename1=section-name1
  filename2=section-name2

  
  
• [Setup Hook]
  This section lists all hook that will be executed before setting up files in [Add.Code] section.

  [Setup Hooks]
  hookname1=section-name4
  hookname2=section-name5
  [hookname1]
  run=extrac32.exe /e /a /y /l c:\MyApplication\client MyApp.cab

  
  
• [Version]
  For compatibility, the following lines must be added if we use hooks
  

  [Version]
  Signature="$CHICAGO$"
  AdvancedINF=2.0

  
  
• [DefaultInstall]
  Installation section that is executed by default. Contains pointers to other sections specifying files to copy and delete, registry updates, .ini file updates, and so on. (for full list of pointer and the systax of this section please refer to here)
  In this post we will just talk about AddReg. AddReg pointer point to a section for adding subkeys or value names to the registory, optionally setting the value.
  
  

  [DefaultInstall]
  AddReg=AddRegSection
  [AddRegSection]
  HKLM,Software\MyApp,ProgramName,,"My Application"
  HKLM,Software\MyApp,"Program Location",,"%25%\MyApp.exe"

  
  
• [Strings]
  Defines one or more strings keys. The Installer expands the strings key to the given string and uses it for further processing. You must enclose a strings key in percent signs (%).
  
  

  [String]
  String0=”MyApplication”
  String1=”Read me”

Reference:
Setup Information File (.inf) Definition
About INF File Architecture

Value at Risk (VaR) – study notes 1

Value at risk (VaR) is a technique used to estimate the probability of portfolio losses based on the statistical analysis of historical price trends and volatilities. It is commonly used  banks and security firms.

VaR contains three components:

1. a relatively high level of confidence (typically either 95% or 99%)
2. a time period (a day, a month or a year) and
3. an estimate of investment loss (expressed either in dollar or percentage terms)

A common statement used in VaR: What is the most I can - with a 95% or 99% level of confidence -  expect to lose in dollars over the next month?

There are three common methods of calculating VaR:

1. The historical method
2. The variance-covariance method
3. The Monte Carlo simulation

The following is an sample implementation of a single stock VaR (download it and run the macro in your local PC).

https://docs.google.com/leaf?id=0B3dIVDUl8UFRNzMyMGNkMjktNGYzYi00OGU1LWFkOWMtZWE5YTJjYjU3NzVh&hl=zh_TW

I would not go into the detail of these three methods, but if you want to know more I suggest you may read John C. Hull reading. Or there is some good online tutorial on finance in the following youtube channel:
http://www.youtube.com/user/bionicturtledotcom

Reference: http://www.mathfinance.cn/value-at-risk/

Google+Facebook

剛獲邀請試用Google+，感覺還好，但暫時用的朋友不多，我想還是要觀察一段時間。

但以下分享的是在Google+上用Facebook的方法，可以減少兩邊走的情況。

http://crossrider.com/install/519-google-facebook

LG Optimus Black (P970) recovery 大法

早一兩天女友的Optimus Black 死了，死因是root 機後delete 多了重要的package，到致以下兩個情況：

1. 開機後，出現LG logo 後十分鐘都不能正常boot 機
2. boot 機後，只出現locked screen，你解lock 後出現空白畫面。

因為小弟是iFan boy，所以不懂得如何復原，所以用了最原始的方法：Full recovery。以下是上網找到的步驟，小弟亦親身驗證了它是work 的。
你需要以下的東西去進行recovery：

a) PC with Internet

b) 你電話的 IMEI 碼 (我的在機內入電池的位置，或打開電話撥*#06#查詢)

c) LGmobile update (B2CAppSetup.exe)
http://www.lg.com/hk/support/mc-support/mobile-phone-support.jsp

Recovery 的步驟：

1. 下載並安裝c
2. 打開LGmobile update
3. 如果你未裝電話的usb driver，到 Options & Help ->  Country & Language
   
4. 在Country 選擇香港
    
5. 然後Click Install USB Driver
   
6. Double click “LGP970”，然後等待安裝完成。
   
    
7. 之後幾步是重點(對不起我沒有cap 圖，因為做這個動作時我沒有準備這篇blog)，關掉你的電話，然後拆下電池。
8. 按著Vol + 並把電話駁到電腦的usb，不要放手，直至window 告訴你它已經安裝好driver (右下角的氣泡提示)。
9. Run LGMobile update(B2CAppSetup) -> Customer support –> Recovery
10. 然後在彈出來的對話框輸入你電話的IMEI，然後按確定。
11. 最後recovery 程式就會開始，靜靜的等待它完成吧。

Reference: http://forum.xda-developers.com/showthread.php?t=1111771&page=5

初探 Internet Component Download

這幾天都在研究 "Internet Component Download” 的資料，以下是一些網上資料的整理 ：

MSDN offical defination

Internet Component Download is a system service for downloading and installing software from Web sites on the Internet and intranets. This service also provides certificate checking. Internet Component Download is supported by Microsoft Internet Explorer 3.0 and later.
You, the software provider or Web master, can "package" components and place them on your Web servers for download. When users visit your Web site, Internet Component Download enables their browsers to pull down and install the programs.

Key Concept

There is some key concepts for this type of software distribution method:

• Carbinet File (.cab) – a package that include all files for the software distribution (e.g.active X controls (.ocx), dll, exe, etc.).   (詳細要怎樣打包我不懂，本身我是JAVA人，m記的東西本來就不太懂，因為工作關係我才接觸這topic)
• Packaging – Code authors need to package the software for user to download. The packaging machanism is usually a cabinet file addressed by the “codebase” attribute of an “object” element on a web page. Here is a piece of sample html code:
  <object classid="clsid:xxxx-xxxx-xxxx"
  codebase="/cab/testing.cab">
  </object>
• Signing – To protect the user from downloading software from the internet, users with user security level set to default level normally cannot download and execute the software (e.g. User Access Control, UAC, in windows 7).
  
  Digitial signature help to associate the software distribution to the code author, providing accountability for software developers.
  
  According to MSDN:
  When a user's security level is set at the default level, any object identified by the OBJECT tag on a Web page must be digitally signed. Internet Explorer's default security setting won't install a component that doesn't have a digital signature.
  
  
  This is a screen capture for the pop-up when you try to download and install an unsigned cabinet file
• Information file (.inf) – This file contain the setup information for Internet Explorer the use to install and register your software distribution. For the usage of INF file, we will discuss in another post.

Reference: MSDN - Introduction to Internet Component Download

Covariance and Correlation Coefficient

Covariance

In probability theory and statistics, covariance is a measure of how much two variables change together.
Variance is a special case of the covariance when the two variables are identical.

For any two assets A & B, the covariance of the return of these two asset in n months is calculated by the following formula:

Cov = 1/(n-1) * Σ _{i = 1 to n} (RA_i – avgRA_i) * (RB_i – avgRB_i)

where
RA_i = Return of asset A in month i
avgRA_i = Average return of asset A in n months
RB_i = Return of asset B in month i
avgRB_i = Average return of asset B in n months

Large positive covariance does not meaning two asset have high correlation. It also depends on their volatility (standard deviation). If the volatility is high, then the corrlation is not high. To solve this problem, we can make use of correlation coefficient of these two assets.

Correlation Coefficient

Correlation coefficient = Cov / (StdA * StdB)

where
StdA = Standard deviation of A
StdB = Standard deviation of B

The value of correlation coefficient will be lie between –1  to +1, for positive value, it mean positive correlation, vice versa.

 

Reference:
綠角財經筆記: 共變異數與相關係數(Covariance and Correlation Cofficient of Financial Assets)
Covariance - Wikipedia, the free encyclopedia
Correlation and dependence - Wikipedia, the free encyclopedia

Statistics Formulas

Parameters

• Population mean = μ = ( Σ X_i ) / N
• Population standard deviation = σ = sqrt [ Σ ( X_i - μ )² / N ]
• Population variance = σ² = Σ ( X_i - μ )² / N
• Variance of population proportion = σ_P² = PQ / n
• Standardized score = Z = (X - μ) / σ
• Population correlation coefficient = ρ = [ 1 / N ] * Σ { [ (X_i - μ_X) / σ_x ] * [ (Y_i - μ_Y) / σ_y ] }

Statistics

Unless otherwise noted, these formulas assume simple random sampling.

• Sample mean = x = ( Σ x_i ) / n
• Sample standard deviation = s = sqrt [ Σ ( x_i - x )² / ( n - 1 ) ]
• Sample variance = s² = Σ ( x_i - x )² / ( n - 1 )
• Variance of sample proportion = s_p² = pq / (n - 1)
• Pooled sample proportion = p = (p₁ * n₁ + p₂ * n₂) / (n₁ + n₂)
• Pooled sample standard deviation = s_p = sqrt [ (n₁ - 1) * s₁² + (n₂ - 1) * s₂² ] / (n₁ + n₂ - 2) ]
• Sample correlation coefficient = r = [ 1 / (n - 1) ] * Σ { [ (x_i - x) / s_x ] * [ (y_i - y) / s_y ] }

Correlation

• Pearson product-moment correlation = r = Σ (xy) / sqrt [ ( Σ x² ) * ( Σ y² ) ]
• Linear correlation (sample data) = r = [ 1 / (n - 1) ] * Σ { [ (x_i - x) / s_x ] * [ (y_i - y) / s_y ] }
• Linear correlation (population data) = ρ = [ 1 / N ] * Σ { [ (X_i - μ_X) / σ_x ] * [ (Y_i - μ_Y) / σ_y ] }

 

Reference: http://stattrek.com/Lesson1/Formulas.aspx?Tutorial=Stat