Semi-Log Graphs

Recently I was introduced to a concept of graphing called semi-log graphing. When most people use graphs, they use linear scales for both the x and y axes, but semi-log graphs use a linear scale for the x axis and a logarithmic scale for the y axis, hence semi-log. How this logarithmic scale works is it goes up from numbers one-ten, then continues as such but with the numbers ten-twenty. Essentially, you ad a zero after the numbers of the scale every ten numbers. This logarithmic scale is very useful for looking at certain functions, like exponential functions. Below are graphs of the functions f(x) = 2^x and g(x) = 3^x on both a semi-log graph and standard graph. You can see the values are much clearer on a semi-log graph, but it can be difficult to recognize the function without understanding the semi-log format.

Standard Graph

Semi-Log Graph