*4.2. Population Diversity*

The population diversity (PD) measure is taken from [51], which is based on the square root of the deviation sum, Equation (25), of individual components and their corresponding mean values, Equation (24):

$$\overline{x\_{j}} = \frac{1}{NP} \sum\_{i=1}^{NP} x\_{j,i} \tag{24}$$

$$PD = \sqrt{\frac{1}{NP} \sum\_{i=1}^{NP} \sum\_{j=1}^{D} \left( x\_{j,i} - \overline{x\_j} \right)^2}. \tag{25}$$

where *i* is the iterator of members of the population and *j* is that of the component (dimension).
