I am trying to follow some instructions given to me for downloading AFNI on ubuntu. The first thing it tells me to do in the terminal is:

sudo yum install libXp tcsh

sudo yum install PyQt4 R

but it says yum: command not found. So I found, online, this command:

sudo apt-get install libXp tcsh

but it tells me E: unable to locate package libXp

also, for PyQt4 and for R

I read online to do:

sudo apt-get update 

and

sudo apt-get upgrade

but it still doesn't work. I read other things about changing sources.list file, but I'm not understanding what I should change in this file. How do I get this to work?

Thanks for any help!