Log transformation (statistics)

In statistics, the log transformation is the application of the logarithmic function to each point in a data set—that is, each data point zi is replaced with the transformed value yi = log(zi). The log transform is usually applied so that the data, after transformation, appear to more closely meet the assumptions of a statistical inference procedure that is to be applied, or to improve the interpretability or appearance of graphs.

Source: Wikipedia — Log transformation (statistics) (CC BY-SA 4.0)