Solve duplicates deeply

Author: ahmedfgad

examples/example_fitness_wrapper.py

@@ -0,0 +1,41 @@
+import pygad
+import numpy
+
+"""
+All the callback functions/methods in PyGAD have limits in the number of arguments passed.
+For example, the fitness function accepts only 3 arguments:
+    1. The pygad.GA instance.
+    2. The solution(s).
+    3. The index (indices) of the passed solution(s).
+If it is necessary to pass extra arguments to the fitness function, for example, then follow these steps:
+    1. Create a wrapper function that accepts only the number of arguments meeded by PyGAD.
+    2. Define the extra arguments in the body of the wrapper function.
+    3. Create an inner fitness function inside the wrapper function with whatever extra arguments needed.
+    4. Call the inner fitness function from the wrapper function while passing the extra arguments.
+
+This is an example that passes a list ([10, 20, 30]) to the inner fitness function. The list has 3 numbers.
+A number is randomly selected from the list and added to the calculated fitness.
+"""
+
+function_inputs = [4,-2,3.5,5,-11,-4.7]
+desired_output = 44
+
+def fitness_func_wrapper(ga_instanse, solution, solution_idx):
+    def fitness_func(ga_instanse, solution, solution_idx, *args):
+        output = numpy.sum(solution*function_inputs)
+        output += numpy.random.choice(args)
+        fitness = 1.0 / (numpy.abs(output - desired_output) + 0.000001)
+        return fitness
+    args = [10, 20, 30]
+    fitness = fitness_func(ga_instanse, solution, solution_idx, *args)
+    return fitness
+
+ga_instance = pygad.GA(num_generations=3,
+                       num_parents_mating=5,
+                       fitness_func=fitness_func_wrapper,
+                       sol_per_pop=10,
+                       num_genes=len(function_inputs),
+                       suppress_warnings=True)
+
+ga_instance.run()
+ga_instance.plot_fitness()