minor = 1e5,1.5e5,2e5,3.5e5,5e5,6e5
major = 0.5e5,2.5e5,4e5,5.5e5
math /xrange 1e3:7e5
margin 0.07
plot log(x)
ticks bottom /minor $(minor) /major $(major) /format="%.1e"
ticks top /minor $(minor) /major $(major)
background-lines bottom Gray /style Dots