Here you can select one of the 36 built-in fitness functions of GeneXproTools 4.0 (Absolute with SR, Absolute/Hits, MSE, RMSE, MAE, RSE, RRSE, RAE, Relative with SR, Relative/Hits, rMSE, rRMSE, rMAE, rRSE, rRRSE, rRAE, R-square, and Correlation Coefficient, together their respective counterparts with parsimony pressure) and, depending on the fitness function, adjust a few parameters, such as the Selection Range and Precision for Relative with SR and Absolute with SR or the Precision for Relative/Hits and Absolute/Hits.

In the Fitness Function Tab used for Classification and Logic Synthesis the 30 built-in fitness functions of GeneXproTools 4.0 are listed (Number of Hits, Hits with Penalty, Accuracy, Squared Accuracy, Sensitivity/Specificity, PPV/NPV, SSPN, R-square, Correlation Coefficient, MSE, RMSE, MAE, RSE, RRSE, and RAE), together with the adjustable 0/1 Rounding Threshold used in Classification problems and fundamental for all fitness functions, including user defined fitness functions.

In addition to the wide variety of GeneXproTools built-in fitness functions, you can also design other fitness functions by selecting Custom in the Fitness Function list box. Indeed, for all problem categories, the Fitness Function Tab is also the place where you can design your own fitness function using the Custom Fitness Function window to write the code of your fitness function. The code for the custom fitness function must be in JavaScript and can be tested before evolving a model with it.