app.py

import numpy as np
import math
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation
from PIL import Image
import gradio as gr
import io
from moviepy.editor import ImageSequenceClip


class Objective:
    def Evaluate(self, p):
        return -5.0*np.exp(-0.5*((p[0]+2.2)**2/0.4+(p[1]-4.3)**2/0.4)) + -2.0*np.exp(-0.5*((p[0]-2.2)**2/0.4+(p[1]+4.3)**2/0.4))

# Create an instance of the Objective class
obj = Objective()

# Evaluate the fitness of a position
position = np.array([-2.2, 4.3])
fitness = obj.Evaluate(position)

print(f"The fitness of the position {position} is {fitness}")

class Bounds:
    def __init__(self, lower, upper, enforce="clip"):
        self.lower = np.array(lower)
        self.upper = np.array(upper)
        self.enforce = enforce.lower()
    
    def Upper(self): 
        return self.upper
    
    def Lower(self): 
        return self.lower
    
    def Limits(self, pos): 
        npart, ndim = pos.shape 
        for i in range(npart):
            for j in range(ndim):
                if pos[i, j] < self.lower[j]:
                    if self.enforce == "clip":
                        pos[i, j] = self.lower[j]
                    elif self.enforce == "resample":
                        pos[i, j] = self.lower[j] + np.random.random() * (self.upper[j] - self.lower[j])
                elif pos[i, j] > self.upper[j]:
                    if self.enforce == "clip":
                        pos[i, j] = self.upper[j]
                    elif self.enforce == "resample":
                        pos[i, j] = self.lower[j] + np.random.random() * (self.upper[j] - self.lower[j])
            pos[i] = self.Validate(pos[i]) 
        return pos
    
    def Validate(self, pos):
        return pos

# Define the bounds
lower_bounds = [-6, -6, -6]
upper_bounds = [6, 6, 6]

# Create an instance of the Bounds class
bounds = Bounds(lower_bounds, upper_bounds, enforce="clip")

# Define a set of positions
positions = np.array([[15, 15], [-15, -15], [5, 15], [15, 5]])

# Enforce the bounds on the positions
valid_positions = bounds.Limits(positions)

print(f"Valid positions: {valid_positions}")

# Define the bounds
lower_bounds = [-6, -6, -6]
upper_bounds = [6, 6, 6]

# Create an instance of the Bounds class
bounds = Bounds(lower_bounds, upper_bounds, enforce="resample")

# Define a set of positions
positions = np.array([[15, 15, 15], [-15, -15, -15], [5, 15, 15], [15, 5, 5]])

# Enforce the bounds on the positions
valid_positions = bounds.Limits(positions)

print(f"Valid positions: {valid_positions}")


class QuasiRandomInitializer:
    def __init__(self, npart=10, ndim=3, bounds=None, k=1, jitter=0.0):
        self.npart = npart
        self.ndim = ndim
        self.bounds = bounds
        self.k = k
        self.jitter = jitter
        self.primes = [
            2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97,
            101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197,
            199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313,
            317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431, 433, 439,
            443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509, 521, 523, 541, 547, 557, 563, 569, 571,
            577, 587, 593, 599, 601, 607, 613, 617, 619, 631, 641, 643, 647, 653, 659
        ]

    def Halton(self, i, b):
        f = 1.0
        r = 0
        while i > 0:
            f = f / b
            r = r + f * (i % b)
            i = math.floor(i / b)
        return r

    def InitializeSwarm(self):
        self.swarm = np.zeros((self.npart, self.ndim))
        lo = np.zeros(self.ndim)
        hi = np.ones(self.ndim)
        if self.bounds is not None:
            lo = self.bounds.Lower()
            hi = self.bounds.Upper()

        for i in range(self.npart):
            for j in range(self.ndim):
                h = self.Halton(i + self.k, self.primes[j % len(self.primes)])
                q = self.jitter * (np.random.random() - 0.5)
                self.swarm[i, j] = lo[j] + (hi[j] - lo[j]) * h + q

        if self.bounds is not None:
            self.swarm = self.bounds.Limits(self.swarm)

        return self.swarm

# Define the bounds
lower_bounds = [-6, -6, -6]
upper_bounds = [6, 6, 6]
bounds = Bounds(lower_bounds, upper_bounds, enforce="clip")

# Create an instance of the QuasiRandomInitializer class
init = QuasiRandomInitializer(npart=50, ndim=3, bounds=bounds)

# Initialize the swarm
swarm_positions = init.InitializeSwarm()

print(f"Initial swarm positions: {swarm_positions}")

# Define the bounds
lower_bounds = [-6, -6, -6]
upper_bounds = [6, 6, 6]
bounds = Bounds(lower_bounds, upper_bounds, enforce="resample")

# Create an instance of the QuasiRandomInitializer class
init = QuasiRandomInitializer(npart=50, ndim=3, bounds=bounds)

# Initialize the swarm
swarm_positions = init.InitializeSwarm()

class GWO:
    def __init__(self, obj, eta=2.0, npart=10, ndim=3, max_iter=200,tol=None,init=None,done=None,bounds=None):   
            self.obj = obj
            self.npart = npart
            self.ndim = ndim
            self.max_iter = max_iter
            self.init = init
            self.done = done
            self.bounds = bounds
            self.tol = tol
            self.eta = eta
            self.initialized = False
        
    def Initialize(self):
        """Set up the swarm"""

        self.initialized = True
        self.iterations = 0
       
        self.pos = self.init.InitializeSwarm()  # initial swarm positions
        self.vpos= np.zeros(self.npart)
        for i in range(self.npart):
            self.vpos[i] = self.obj.Evaluate(self.pos[i])
            
        # Initialize the list to store positions at each iteration
        self.all_positions = []
        self.all_positions.append(self.pos.copy())  # Store the initial positi

        #  Swarm bests
        self.gidx = []
        self.gbest = []
        self.gpos = []
        self.giter = []
        idx = np.argmin(self.vpos)
        self.gidx.append(idx)
        self.gbest.append(self.vpos[idx])
        self.gpos.append(self.pos[idx].copy())
        self.giter.append(0)

        #  1st, 2nd, and 3rd best positions
        idx = np.argsort(self.vpos)
        self.alpha = self.pos[idx[0]].copy()
        self.valpha= self.vpos[idx[0]]
        self.beta  = self.pos[idx[1]].copy()
        self.vbeta = self.vpos[idx[1]]
        self.delta = self.pos[idx[2]].copy()
        self.vdelta= self.vpos[idx[2]]

     # *** Gradio app method optimize created [leveraged vis-a-vis optimize function on the outside of the underlying anatomy of GWO class] ***
    def optimize(self):
        """
        Run a full optimization and return the best positions and fitness values.
        This method is designed to be used with Gradio.
        """
        # Initialize the swarm
        self.Initialize()

        # Lists to store the best positions and fitness values at each step
        best_positions = []
        best_fitness = []

        # Main loop
        while not self.Done():
            self.Step()  # Perform an optimization step
            # Update best_positions and best_fitness with the current best values
            best_positions.append(self.gbest[-1])
            best_fitness.append(self.gpos[-1])

        # Print the best positions and fitness found
        print("Best Positions:", best_positions)
        print("Best Fitness:", best_fitness)

        # Return the best positions and fitness after the optimization
        return best_positions, best_fitness

    def Step(self):
        """Do one swarm step"""
        print("Inside Step method")
        
        #  a from eta ... zero (default eta is 2)
        a = self.eta - self.eta*(self.iterations/self.max_iter)
        print("a:", a)

        #  Update everyone
        for i in range(self.npart):
            A = 2*a*np.random.random(self.ndim) - a
            C = 2*np.random.random(self.ndim)
            Dalpha = np.abs(C*self.alpha - self.pos[i]) 
            X1 = self.alpha - A*Dalpha

            A = 2*a*np.random.random(self.ndim) - a
            C = 2*np.random.random(self.ndim)
            Dbeta = np.abs(C*self.beta - self.pos[i]) 
            X2 = self.beta - A*Dbeta

            A = 2*a*np.random.random(self.ndim) - a
            C = 2*np.random.random(self.ndim)
            Ddelta = np.abs(C*self.delta - self.pos[i]) 
            X3 = self.delta - A*Ddelta 
            
            self.pos[i,:] = (X1+X2+X3) / 3.0

        #  Keep in bounds
        if (self.bounds != None):
            self.pos = self.bounds.Limits(self.pos)

        #  Get objective function values and check for new leaders
        for i in range(self.npart):
            self.vpos[i] = self.obj.Evaluate(self.pos[i])

            #  new alpha?
            if (self.vpos[i] < self.valpha):
                self.vdelta = self.vbeta
                self.delta = self.beta.copy()
                self.vbeta = self.valpha
                self.beta = self.alpha.copy()
                self.valpha = self.vpos[i]
                self.alpha = self.pos[i].copy()

            #  new beta?
            if (self.vpos[i] > self.valpha) and (self.vpos[i] < self.vbeta):
                self.vdelta = self.vbeta
                self.delta = self.beta.copy()
                self.vbeta = self.vpos[i]
                self.beta = self.pos[i].copy()
            
            #  new delta?
            if (self.vpos[i] > self.valpha) and (self.vpos[i] < self.vbeta) and (self.vpos[i] < self.vdelta):
                self.vdelta = self.vpos[i]
                self.delta = self.pos[i].copy()

            #  is alpha new swarm best?
            if (self.valpha < self.gbest[-1]):
                self.gidx.append(i)
                self.gbest.append(self.valpha)
                np.save('best_fitness.npy', np.array(self.gbest))
                self.gpos.append(self.alpha.copy())
                np.save('best_positions.npy', np.array(self.gpos))
                # Save the positions at the current iteration
                self.all_positions.append(self.pos.copy())
                self.giter.append(self.iterations)

        self.iterations += 1
        print("Iteration:", self.iterations)
    
    def Done(self):
        """Check if we are done"""

        if (self.done == None):
            if (self.tol == None):
                return (self.iterations == self.max_iter)
            else:
                return (self.gbest[-1] < self.tol) or (self.iterations == self.max_iter)
        else:
            return self.done.Done(self.gbest,
                        gpos=self.gpos,
                        pos=self.pos,
                        max_iter=self.max_iter,
                        iteration=self.iterations)
    
    def Evaluate(self, pos):
        p = np.zeros(self.npart) 
        for i in range(self.npart):
            p[i] = self.obj.Evaluate(pos[i]) 
        return p

    def animate_particles(self, obj, goal, frames=100, interval=50):
        """Create a 2D contour particle animation"""
        # Define the range for the x and y axis
        x_range = np.linspace(self.bounds.Lower()[0], self.bounds.Upper()[0], 100)
        y_range = np.linspace(self.bounds.Lower()[1], self.bounds.Upper()[1], 100)

        # Create a grid of points
        X, Y = np.meshgrid(x_range, y_range)
        Z = np.zeros_like(X)

        # Evaluate the objective function on the grid
        for i in range(X.shape[0]):
            for j in range(X.shape[1]):
                Z[i, j] = obj.Evaluate(np.array([X[i, j], Y[i, j]]))

        # Create a figure and axis
        fig, ax = plt.subplots(figsize=(8, 6))

        # Plot the contour
        contour = ax.contour(X, Y, Z, levels=20, colors='k', alpha=0.5)

        # Plot the goal
        goal_plot, = ax.plot([], [], 'r*', markersize=10)

        # Initialize the scatter plot for the particles
        scat = ax.scatter([], [], color='blue', s=20)

        # Function to update the scatter plot
        def update(frame):
            # Perform one step of the GWO algorithm
            self.Step()
            # Update the scatter plot with the new positions
            scat.set_offsets(self.pos)
            # Update the goal position if it has changed
            goal_plot.set_data([goal[0]], [goal[1]])  # Pass a list or a NumPy array
            return scat, goal_plot

        # Create the animation
        anim = FuncAnimation(fig, update, frames=frames, interval=interval, blit=True)

        # Show the plot
        plt.show()
        # Save the frames as images
        images = []
        for i in range(frames):
            anim.func_args = (i,)
            anim._step()
            fig.canvas.draw()
            # Convert the figure to an image
            image_data = np.frombuffer(fig.canvas.tostring_rgb(), dtype='uint8')
            image = Image.frombytes('RGB', fig.canvas.get_width_height(), image_data)
            images.append(image)
            
        # Close the figure to free up memory
        plt.close(fig)
        
        # Convert the list of images to a list of PIL images
        pil_images = [Image.fromarray(np.array(img)) for img in images]
        
        # Create a video from the images
        # After generating the images, create a video from them
        frames_per_second = 30  # Adjust this to your desired frame rate
        clip = ImageSequenceClip(pil_images, fps=frames_per_second)
        clip.write_videofile(video_path, codec='libx264', audio=False)

        
        # Return the video path
        return video_path



# Define goal outside of the optimize function
#goal = (-2.2, 4.3)  # Example goal position

def optimize(npart, ndim, max_iter, goal_x, goal_y, frames, interval):
    # Create the goal tuple from the X and Y coordinates
    goal = (goal_x, goal_y)

    # Initialize the GWO algorithm with the provided parameters
    gwo = GWO(obj=obj, npart=npart, ndim=ndim, max_iter=max_iter, init=init, bounds=bounds)
    
    # Run the optimization
    best_positions, best_fitness = gwo.optimize()

    # Get the best fitness and positions at the last iteration
    last_best_fitness = best_fitness[-1]
    last_best_positions = best_positions[-1]

    # Format the output strings
    best_fitness_text = f"Best Positions: {last_best_fitness}"
    best_positions_text = f"Best Fitness: {last_best_positions}"

    # Animate the particles
    video_path = gwo.animate_particles(obj=obj, goal=goal, frames=frames, interval=interval)
    
    # Return the path to the video file
    return video_path, best_fitness_text, best_positions_text

# Define the Gradio interface
iface = gr.Interface(
    fn=optimize,  # Pass the optimize function object
    inputs=[
        gr.components.Slider(10, 50, 50, step=1, label="Number of Wolves"),
        gr.components.Slider(3, 3, 3, step=1, label="Number of Dimensions"),
        gr.components.Slider(100, 200, 200, step=1, label="Maximum Iterations"),
        gr.components.Slider(-5, 5, 2.2, label="Goal Position X"),
        gr.components.Slider(-5, 5, 4.3, label="Goal Position Y"),
        gr.components.Slider(100, 200, 100, step=1, label="Frames"),
        gr.components.Slider(50, 100, 50, step=1, label="Interval"),
    ],
    outputs=[
        gr.components.Video(format="mp4"),
        gr.components.Textbox(label="Best Fitness"),
        gr.components.Textbox(label="Best Positions"),
    ],
)

# Launch the interface
iface.launch()