How to install pgfplots in Ubuntu 12.04.3 LTS from Terminal?

I have the following:

a@a-Compaq-Presario-C700-Notebook-PC:~$ pdflatex --version 
pdfTeX 3.1415926-1.40.10-2.2 (TeX Live 2009/Debian)
kpathsea version 5.0.0
Copyright 2009 Peter Breitenlohner (eTeX)/Han The Thanh (pdfTeX).
There is NO warranty.  Redistribution of this software is
covered by the terms of both the pdfTeX copyright and
the Lesser GNU General Public License.
For more information about these matters, see the file
named COPYING and the pdfTeX source.
Primary author of pdfTeX: Peter Breitenlohner (eTeX)/Han The Thanh (pdfTeX).
Compiled with libpng 1.2.46; using libpng 1.2.46
Compiled with zlib; using zlib
Compiled with poppler version 0.18.2


My texlive version has no problem.

a@a-Compaq-Presario-C700-Notebook-PC:~$ sudo apt-get install texlive
Reading package lists... Done
Building dependency tree       
Reading state information... Done
texlive is already the newest version.
The following packages were automatically installed and are no longer required:
  linux-headers-3.2.0-29-generic linux-headers-3.2.0-29
Use 'apt-get autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.