Semi-log Plots

Every exponential graph in this unit has been a curve that rises slowly and then shoots off the top of the page. That shape makes two things hard. First, it's hard to judge by eye whether data is really exponential. Second, numbers like 250 and 6,490 can't both be read clearly on the same axis. A semi-log plot fixes both problems. It stretches the y-axis logarithmically, and on that axis every exponential function becomes a straight line.