mutate function done?

03_euler_gen_alg/main.py

@@ -18,17 +18,20 @@ import utils
 POPULATION_SIZE = 10
 SELECTION_SIZE = (POPULATION_SIZE * 7) // 10  # 70% of population, rounded down for selection
 CROSSOVER_PAIR_SIZE = (POPULATION_SIZE - SELECTION_SIZE) // 2  # pairs needed for crossover
-XOVER_POINT = 3
+XOVER_POINT = 3 # 4th position
+MUTATION_BITS = POPULATION_SIZE * 1
 
 fitness = 0.01
 pop_grey = []
-pop_bin = []
+pop_bin = [] # 32 Bit Binary
 pop_bin_params = []
-pop_new = []
+pop_new = [] # 32 Bit Grey-Code as String
 
 e_func = lambda x: np.e**x
 
 def generate_random_population():
+    """ Puts random 32 Bit binary strings into 4 * 8 Bit long params. """
+    # Random population array
     for i in range(POPULATION_SIZE):
         pop_grey[i] = format(random.getrandbits(32), '32b')
         pop_bin[i] = utils.grey_to_bin(pop_grey[i])
@@ -45,7 +48,7 @@ def quadratic_error(original_fn, approx_fn, n):
     return error
 
 def eval_fitness(pop_bin_values):
-    """ Returns an array with fitness value of every individual in a population."""
+    """ Returns an array with fitness value of every individual in a population. """
     fitness_arr = []
     for params in pop_bin_values:    
         # Convert binary string to parameters for bin_values
@@ -61,9 +64,10 @@ def eval_fitness(pop_bin_values):
         
     return fitness_arr
 
-def select(fitness_arr):
+def select(population, fitness_arr):
     sum_of_fitness = sum(fitness_arr) 
-    while len(pop_new) < SELECTION_SIZE:
+    while len(population) < SELECTION_SIZE:   
+        # Roulette logic
         roulette_num = random.random()
         is_chosen = False
         while not is_chosen:
@@ -71,8 +75,8 @@ def select(fitness_arr):
             for i, fitness in enumerate(fitness_arr):
                 cumulative_p += fitness / sum_of_fitness
                 if roulette_num < cumulative_p:
-                    # Add the 32 Bit individual in grey code to pop_new
-                    pop_new.append(pop_grey[i])
+                    # Add the 32 Bit individual in grey code to population
+                    population.append(pop_grey[i])
                     
                     # Calc new sum of fitness
                     fitness_arr.pop(i)
@@ -81,30 +85,59 @@ def select(fitness_arr):
                     is_chosen = True # break while loop
                     break # break for loop
            
-def xover():
-    # calc how many pairs are possible with pop_new
-    individual_a = pop_new[0]
-    individual_b = pop_new[1]
+def xover(population, xover_rate):
+    """Performs crossover on pairs of individuals from population."""
+    offspring = []
     
-    
-    # get first three pairs in pop_new
-    # do the crossover
+    # Process pairs while we have enough individuals and haven't reached CROSSOVER_PAIR_SIZE
+    pair_count = 0
+    i = 0
+    while i < len(population) - 1 and pair_count < xover_rate:
+        parent_a = population[i]
+        parent_b = population[i + 1]
+        
+        # Create two new offspring by swapping parts at XOVER_POINT
+        offspring_a = parent_a[:XOVER_POINT] + parent_b[XOVER_POINT:]
+        offspring_b = parent_b[:XOVER_POINT] + parent_a[XOVER_POINT:]
+        
+        offspring.extend([offspring_a, offspring_b])
+        pair_count += 1
+        i += 2  # Move to next pair
+        
+    return offspring
+
+def mutate(population, mutation_rate):
+    """Mutate random bits in the population with given mutation rate"""
+    for _ in range(mutation_rate):
+        # Select random individual and convert to list for efficient modification
+        random_num = random.randrange(POPULATION_SIZE)
+        bits = list(population[random_num])
+        
+        # Flip random bit
+        bit_pos = random.randrange(32)
+        bits[bit_pos] = '1' if bits[bit_pos] == '0' else '0'
+        
+        # Convert back to string and update population
+        population[random_num] = ''.join(bits)      
          
 def main():
     pop_bin_values = generate_random_population(10)
-    while fitness > 0.01:  
+    while fitness > 0.01:
         
         # Evaluate fitness
         fitness_arr = eval_fitness(pop_bin_values)    
           
         # Selection        
-        select(fitness_arr) # Alters pop_new
+        select(pop_new, fitness_arr) # Alters pop_new
                 
         # Crossover        
+        offspring = xover(pop_new, CROSSOVER_PAIR_SIZE)
+        pop_new.extend(offspring)  # .extend needed
         
-        # mutation
+        # Mutation
+        mutate(pop_new, MUTATION_BITS)
         
-        # pop_grey = pop_new
+        pop_grey = pop_new
     return 0
 
 if __name__ == "__main__":

03_euler_gen_alg/utils.py

@@ -14,7 +14,7 @@ def bin_to_grey(binary):
     return format(gray, f'0{len(binary)}b')  # Convert back to binary string with same length
 
 def bin_to_param(binary, q_min = 0.0, q_max = 10.0):
-    """Convert binary string to float parameter in range [q_min, q_max]"""
+    """Convert one binary string to float parameter in range [q_min, q_max]"""
     val = int(binary, 2) / 25.5 * 10 # conversion to 0.0 - 10.0 float
     # Scale to range [q_min, q_max]
     q = q_min + ((q_max - q_min) / (2**len(binary))) * val