Wednesday, October 27, 2010

Drawing in Latex with latexdraw

There are several drawing tools for latex.  xfig, skencil and landscape are typical ones.

However, I found by chance that latexdraw is the most convenience one which can automatically produce latex code for use in latex. Also, it supports pdf exportation.

Sunday, October 17, 2010

asymmetric spacings at equal signs using package {cases} in Latex

It is quite annoying that the spaces between the equal sign are not equal if we use \begin{cases}\end{cases}  or \begin{array}\end{array} to produce the left curly bracket.

I found by chance that \begin{aligned} \end{aligned} can solve this problem perfectly. Thanks  amsmath package which gives such an command.

    \dot{x}(t) & = f(x(t), y(t)),\\
 \dot{y}(t) & = g(x(t),\,y(t)).


Sunday, October 03, 2010

Install Adobe reader in Ubuntu and up on 64-bit PC

All the copies of Adobe Reader available at do not work for 64-bit PC ubuntu machine.  Here is how I made it:

1. Follow the steps in the website to enable extra repositories in ubuntu. Namely, go to Administration->Software Sources->Other Software->

Add "deb lucid free non-free",  if the Ubuntu is 10.04;

For Ubuntu 9.10, you should substitute karmic for lucid
For Ubuntu 9.04, you should substitute jaunty for lucid
For Ubuntu 8.04, you should substitute hardy for lucid

2. Reload Software sources when step 1 is finished.

3. Use synaptic package mahager to find acroread

or in terminal

# sudo apt-get install acroread

4. The system will automatically find a right copy your 64-bit system.