Understanding logarithmic plots
More often than not, while reading daily newspapers and similar articles, one can find charts that are used by media organizations to misrepresent the facts. One usual example is using linear scales to create, so called, panic charts where constantly growing value is followed for long period of time (years) and starting values are smaller from latest one by several magnitudes. These values when visualized correctly, would (and usually should), produce linear or almost linear charts. This takes some panic out of the articles they illustrate.
Getting ready
With the logarithmic scale, the ratio of consecutive values is constant. This is important when we are trying to read log plots. With linear (arithmetic) scales, the constant is the distance between consecutive values. In other words, logarithmic plots have constant distance in orders of magnitude. We will see this illustrated on the following plots. The code used to produce this figure is explained here.
As...
