Gene Expression Programming - The Basic Gene Expression Algorithm

The Basic Gene Expression Algorithm

The fundamental steps of the basic gene expression algorithm are listed below in pseudocode:

1. Select function set;

2. Select terminal set;

3. Load dataset for fitness evaluation;

4. Create chromosomes of initial population randomly;

5. For each program in population:

a) Express chromosome;

b) Execute program;

c) Evaluate fitness;

6. Verify stop condition;

7. Select programs;

8. Replicate selected programs to form the next population;

9. Modify chromosomes using genetic operators;

10. Go to step 5.

The first four steps prepare all the ingredients that are needed for the iterative loop of the algorithm (steps 5 through 10). Of these preparative steps, the crucial one is the creation of the initial population, which is created randomly using the elements of the function and terminal sets.