A collection of useful Stargazing resources

Books:

NightWatch: A practical Guide to Viewing the Universe  by Terence Dickinson

  • ISBN-13: 978-1554071470

Computer Desktop Software:

http://www.stellarium.org/  (Support multi-language, multi-platform) The best software to learn the sky, one of the most powerful app.

iPad:

Stellarium: Not as good as Desktop version, but very useful, English only

Star Walk HD: excellent UI, show detail star info, multi-language support

Startracker HD: best UI, easy to use

iPhone:

Startracker: similar to iPad one

SkySafari

Useful knowledge and resources:

Clear Sky Chart:

http://cleardarksky.com/csk/

Light Pollution Atlas 2006 on Google map:

http://djlorenz.github.io/astronomy/lp2006/overlay/dark.html

Observe Solar system stars:

http://www.cfa.harvard.edu/pao/skyreport/solar_system.html

Weekly tips:

http://stardate.org/nightsky/weekly

Continue reading A collection of useful Stargazing resources

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List of common decompress & compress tools in unix

For my future reference:  (整理自互联网)

check folder size:

du -sh *

————

1. 7-zip:  (.7z file)

官网下载地址:http://www.7-zip.org/download.html
源文件项目地址:http://sourceforge.net/projects/p7zip/,目前最新版为9.20.1。
执行以下命令下载安装:

wget http://nchc.dl.sourceforge.net/project/p7zip/p7zip/9.20.1/p7zip_9.20.1_src_all.tar.bz2
tar -jxvf p7zip_9.20.1_src_all.tar.bz2
cd p7zip_9.20.1
make
make install

使用7zip的命令是7za。
安装完成后的使用方法:
7za {a|d|l|e|u|x} 压缩包文件名 {文件列表或目录,可选}

a 向压缩包里添加文件或创建压缩包,如向001.7z添加001.jpg,执行:7za a 001.7z 001.jpg;将001目录打包执行:7za a 001.7z 001;
d 从压缩里删除文件,如将001.7z里的001.jpg删除,执行:7za d 001.7z 001.jpg
l 列出压缩包里的文件,如列出001.7z里的文件,执行:7za l 001.7z
e 解压到当前目录,目录结构会被破坏,如001.rar内有如下目录及文件123/456/789.html,
执行:7za e 001.rar,目录123和456及文件789.html都会存放在当前目录下。
x 以完整路径解压。

zip文件解压中文文件乱码问题,由于zip文件中没有声明其编码,所以在Linux上使用unzip解压以默认编码解压,中文文件名会出现乱码。

————–

2. tar:  (decompress)

  1. Type at the command prompt
    tar xvzf file-1.0.tar.gz – to uncompress a gzip tar file (.tgz or .tar.gz)
    tar xvjf file-1.0.tar.bz2 – to uncompress a bzip2 tar file (.tbz or .tar.bz2)
    tar xvf file-1.0.tar – to uncompressed tar file (.tar)
    • x = eXtract, this indicated an extraction c = create to create )
    • v = verbose (optional) the files with relative locations will be displayed.
    • z = gzip-ped; j = bzip2-zipped
    • f = from/to file … (what is next after the f is the archive file)
  2. The files will be extracted in the current folder (most of the times in a folder with the name ‘file-1.0’).

Continue reading List of common decompress & compress tools in unix

Using Stanford Phoenix++ MapReduce to count the most frequent words in Wikipedia Database

Log of a quick and fun afternoon project.

1. Download Wikipedia English-language Database:

http://en.wikipedia.org/wiki/Wikipedia:Database_download

Download pages-articles.xml.bz2

Uncompress it ro pages-articles.xml (around 45GB)

2. Download Phoenix++:

http://mapreduce.stanford.edu/

http://mapreduce.stanford.edu/plus/phoenix++-1.0.tar.gz

make binary file and then find ‘word_count’ in ‘tests’ folder

3. copy wordcount and pages-articles.xml to the same folder

./word_count pages-articles.xml 1000 >wikiwords.txt

Using wordcount program to count top 1000 popular words from wiki database

4. Result: (Using 8 Xeon E5 server, 128 processing cores) Continue reading Using Stanford Phoenix++ MapReduce to count the most frequent words in Wikipedia Database

关于二手车的选购检查

早先看到一段AMMO NYC 和/Drive Network上的一段视频,关于Used Car Pre-Purchase Inspection. 其中包含了一个详细的检查项目check list,现在回想十分有用,找出链接来.

链接中的pdf包含了详尽的检查项目列表,无论是已有车维护,或是挑选Used Car都十分有用

Reference:

PRE-PURCHASE INSPECTION CHECK LIST:

http://www.ammonyc.com/detailing/pre-purchase-inspection/

http://www.ammonyc.com/wp-content/uploads/2013/07/301-03_DC_201_StepbyStep_R1B.pdf

Continue reading 关于二手车的选购检查

Install github atom text editor on Ubuntu 14.04 x64

Official guide:

https://github.com/atom/atom/blob/master/docs/build-instructions/linux.md

Quote here:

  git clone https://github.com/atom/atom
  cd atom
  script/build # Creates application at /tmp/atom-build/Atom
  sudo script/grunt install # Installs command to /usr/local/bin/atom
  script/grunt mkdeb # Generates a .deb package at /tmp/atom-build

My log (for future re-installation): current version 0.95-f86280a

#**********************
#go to http://nodejs.org/download/
#download node.js source code
cd ~/tmp/nodejs
wget  http://nodejs.org/dist/v0.10.28/node-v0.10.28.tar.gz
tar xzvf node-v0.10.28.tar.gz
cd node-v0.10.28
./configure
./make test
#if failure occures at any stage, fix those. In my case, I failed at 'curl'.
sudo apt-get install curl
./make
sudo make install
#***********************
sudo apt-get install npm
sudo apt-get install libgnome-keyring-dev
sudo npm config set python /usr/bin/python2 -g
#*************************
cd ~/tmp/atom
git clone https://github.com/atom/atom
cd atom/script
sudo ./build
#err occurs at build: node-gyp, my solution:
sudo apt-get remove gyp
#This works
sudo ./build  #this will create app at /tmp/atom-build/Atom
#**************************
cd ~/atom/atom
sudo npm install -g grunt-cli
#don't know if above command is necessary or not
npm install
cd build
sudo grunt install #this will install atom to /usr/local/bin/atom
sudo grunt mkdeb #this will make .deb package at /tmp/atom-build
#****************************
#Finished!
#To run
sudo atom
#package management
apm

 

简易六分仪与夜晚纬度估测

一直想实践一下使用六分仪(Sextant), 简单估计一下纬度.

需要以下材料:

1. 30cm直尺一把 (至少16cm)

2. 量角器.  (没有怎么办? 我网上找了一个pdf打印了一个http://www.ossmann.com/protractor/)

3. 细绳子一条 (实践下来细一些,柔软的比较好)

4.重物 (硬币,回形针)

5. 胶带, 白纸

方法:

1.将绳子一端固定在量角器中央(90度与180度延长线交点),确保绳子能以量角器中央自由旋转(这点很重要,必须是绕着这一点旋转,不能高也不能低).

2. 绳子另一端用胶带固定一个重物

3.将量角器180度边与直尺一边对齐,将量角器倒着固定在靠近尺子左端约2-3cm处 (量角器刻度左边是0度,右边是180度). 量角器与直尺中间夹一张白纸

4. 在户外,找到北极星(北斗七星勺子末端延长5倍). 将尺子右端瞄准北极星, 从左端望去,确保直尺左端,右端,北极星成一条直线.

5.这时候绳子自由悬挂的角度,在量角器上读出z. 例如读出55度,那么90度减去这个度数,就是纬度了,这个例子中纬度就是35度

借用一张引用源的图片来说明:

sextant

Continue reading 简易六分仪与夜晚纬度估测