To get pgfplots you can use the ppa by johannes Reinhardt
ppa:johannes-reinhardt/ppa
but the newers build of pgfplots is for lucid so if you are on a newer ubuntu you need to change the release name from e.g. precise to lucid in the software manager. Another way is to manually add
deb http://ppa.launchpad.net/johannes-reinhardt/ppa/ubuntu lucid main
deb-src http://ppa.launchpad.net/johannes-reinhardt/ppa/ubuntu lucid main
to /etc/apt/sources.list
and to get the key by:
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 5FBD6912
now you can apt-get update and install pgfplots
Tags: pgfplots