If you're trying to figure out what all this log stuff is about, try plotting the same graph on regular graph paper. Actually, all you really need to do is try to put numbers on either of the axes - you should figure it out pretty quickly.
I may try to put more information here if I get a lot of questions. My (Arndt Laemmerzahl's) students ONLY, feel free to contact me for advice by clicking on my address: alaemmer@gmu.edu