Fig. 8

Box-counting estimation of fractal dimension (FD). a, Fractal dimension is calculated as the slope of the relationship between log(1/s) and log N(s), where s is the length of box edge and N(s) is the number of boxes required to cover the object. Steeper slopes are associated with increased topographical complexity; b, the local slopes as calculated between sequential data points of Fig. 8a. When objects are said to exhibit ‘true’ fractal behaviour, the local slope will plateau over a range of box sizes. In this instance, it is clear that no such plateaus occur, and thus bacula cannot be considered ‘fractal’