This morning I wrote up this quick and easy way to get actual numbers out of graphs and whatnot that show up in journal articles.
$ pdfimages article.pdf fig $ clickloc.tk fig-000.ppm > fig-000.pixels $ scale_click.py 0 10 5 20 fig-000.pixels > fig-000.data
Just use your first four clicks in clickloc.tk to mark out the x and y minimum and maximum values. Then use to convert the pixel values to the units listed in the figure. In my example, the x axis ran from 0 to 10 units, and the y axis ran from 5 to 20 units. Supports log-scaled axes too.
Having gotten some numbers, my sawtooth simulator matches up fairly well to Schlierf & Rief's results on both models. Hooray! ;).