I just added these to my sources.list and apt-get update throws this up

Failed to fetch
302 Found Failed to fetch 302 Found Reading
Package Lists... Done
W: Couldn't stat source package list
packages/ Packages
(/var/lib/apt/lists/anakonda.altervista.org_debian_packages_Packages) - stat
(2 No such file or directory)

As instructed on the matplot lib homepage, my sources.list has

deb packages/ deb-src sources/