search for: prefixpairs

i want to plot values with frequency on a logarithmic x axis. similar to this example that i found in the web: http://www.usspeaker.com/jensen%20p15n-graph.gif I would like to convert long numbers to si prefix notation like in the example (200000 to 200k, 35000000 to 3.5 M) Of course i could create labels by hand, but i have many files so i need some automatic function. Has anyone done that