math input test

Einstein's most famous equation is $E=mc^2$.
Newton derived the equation [s=ut+\sfrac{1}{2}at^2]

$\sum_i^2$

PyPI mirror error

Copying /packages/source/Q/Quotient/Quotient-0.3.0.tar.gz
Traceback (most recent call last):
  File "/usr/local/bin/pep381run", line 30, in <module>
    state.synchronize()
  File "/usr/local/lib/python2.7/dist-packages/pep381client/__init__.py", line 119, in synchronize
    self._synchronize()
  File "/usr/local/lib/python2.7/dist-packages/pep381client/__init__.py", line 159, in _synchronize
    self.maybe_copy_file(project, file)
  File "/usr/local/lib/python2.7/dist-packages/pep381client/__init__.py", line 247, in maybe_copy_file
    data = r.read()
  File "/usr/lib/python2.7/httplib.py", line 548, in read
    s = self._safe_read(self.length)
  File "/usr/lib/python2.7/httplib.py", line 647, in _safe_read
    chunk = self.fp.read(min(amt, MAXAMOUNT))
  File "/usr/lib/python2.7/socket.py", line 380, in read
    data = self._sock.recv(left)
socket.error: [Errno 104] Connection reset by peer

latex bibtex installation and usage under ubuntu

#install latex under ubuntu
sudo apt-get install texlive
sudo apt-get install texlive-ful
sudo apt-get install gedit-latex-plugin # need to activate the plugin in the gedit->edit->preferences->plugins

#other packages recommended

sudo apt-get install texlive-fonts-recommended latex-beamer texpower texlive-pictures texlive-latex-extra texpower-examples imagemagick


#using in the bash console
latex filename.tex
bibtex filename.aux
latex filename.tex
latex filename.tex

#view the file
xdvi filename
dvips filename # change into .ps file
gv filename.ps # view the .ps file with gv
ps2pdf filename.ps # change into .pdf file from .ps file

Reference:
 http://linuxandfriends.com/2009/10/06/install-latex-in-ubuntu-linux/
 https://help.ubuntu.com/community/LaTeX
 http://www.ccrnp.ncifcrf.gov/~toms/latexforbeginners.html

ubuntu dpkg no lock and status file

Problem:

Upgrade Ubuntu from 12.04 to 12.10 needs a long time, so I just keep the laptop to upgrade unplugged, when getting up, found the dpkg locked for the unusual shutdown, the stupid thing I did is:

Delete the lock, and the dpkg folder

The errors I got is:
       1) Could not open lock file /var/lib/dpkg/lock - open (2: No such file or directory)
       2) Unable to lock the administration directory (/var/lib/dpkg/), are you root?

Solution:

1) sudo mkdir /var/lib/dpkg/
    error 1) and 2) would disappear, however when apt-get update, a new error comes out:

    Could not open file /var/lib/dpkg/status - open (2: No such file or directory)

2) sudo cp /var/backups/dpkg.status.0 /var/lib/dpkg/status

Now it works fine. 

Thanks the following references:

http://www.linuxquestions.org/questions/linux-software-2/e-unable-to-lock-the-administration-directory-var-lib-dpkg-are-you-root-886443/

http://ubuntuforums.org/showthread.php?t=2008867

bible for phd

Since the master period, I am often excited when finding some academic advices, online academic tutorials and public courses online, however, just after a while, I will lost them, even I often bookmarks them. This needs becoming much more strong when stepping into the phd candidates group. So this ideas comes out, why not build a site to share the open sources for the phd guys, and provide a way to find the online related material quickly and easily. This is the bible4phd mainly for. Hoping it works. Cheers.

Double Seventh Festival

Today is the Double Seventh Festival of China, just like the valentine's day in the western country. This is also my fouth thursday since arriving in Singapore, where I will spend my next four years or more. So I am thinking why not record the hard life so called, for english practice, or for watching my struggling lives.