Python Forum

hi,

I'm currently trying to create a Python code that visualizes the mandelbrot set and Julia set fractal in subplots where the Julia set will be plotted based on the value chosen by clicking on the mandelbrot set plot. When a new point is clicked on the Mandelbrot set plot, the previous visualization of julia set will be replaced by the new one and so does its colorbar.

However, when clicking a new point, the previous colorbar for julia plot does not be removed and replaced with a new one but they both appear on the subplot and keep adding as I clicked a new point.

Is there e any way to solve this?

This is the code that I got.

Thank you.

import numpy as np
import matplotlib.pyplot as plt

#define Mandelbrot function
def mandelbrot(c, max_iter):
    z = 0
    for n in range(max_iter):
        if abs(z) > 2:
            return n  # Number of iterations before diverging
        z = z**2 + c
    return max_iter

#creating fractal (2D array representing Mandelbrot set over a defined region)
def create_M_fractal(M_xmin, M_xmax, M_ymin, M_ymax, width, height, max_iter):
    real_axis = np.linspace(M_xmin, M_xmax, width)
    imag_axis = np.linspace(M_ymin, M_ymax, height)
    return np.array([[mandelbrot(complex(x, y), max_iter) for x in real_axis] for y in imag_axis])

# Parameters for the Mandelbrot set
M_xmin, M_xmax, M_ymin, M_ymax = -2.0, 1.0, -1.5, 1.5
width, height = 800, 800
max_iter = 100

# Generate the Mandelbrot set
M_fractal = create_M_fractal(M_xmin, M_xmax, M_ymin, M_ymax, width, height, max_iter)

# Create subplot
fig, (ax1, ax2) = plt.subplots(nrows=1, ncols=2, figsize=(15, 7))

# Create the main plot for the Mandelbrot set
cax1 = ax1.imshow(M_fractal, extent=(M_xmin, M_xmax, M_ymin, M_ymax), cmap='hot', origin='lower')
ax1.set_title('Mandelbrot Set')
ax1.set_xlabel('Real Part')
ax1.set_ylabel('Imaginary Part')

# Colorbar for Mandelbrot
plt.colorbar(cax1, ax=ax1)



#Define Julia set
def julia(c, max_iter, J_xmin, J_xmax, J_ymin, J_ymax, width, height):
    z = np.linspace(J_xmin, J_xmax, width).reshape((1, width)) + \
        1j * np.linspace(J_ymin, J_ymax, height).reshape((height, 1))
    img = np.zeros(z.shape, dtype=int)
    
    for n in range(max_iter):
        mask = np.abs(z) <= 2
        img[mask] = n
        z[mask] = z[mask]**2 + c
    
    return img

# Parameters for Julia
J_xmin, J_xmax, J_ymin, J_ymax = -2.0, 2.0, -1.5, 1.5
width, height = 800, 800
max_iter = 100

# Function to update the Julia set based on the clicked point
def update_julia(event):
    if event.inaxes == ax1:  # Check if click is in subplot 1
        if event.xdata is not None and event.ydata is not None:
            # Get the clicked point
            x = event.xdata
            y = event.ydata
            c = complex(x, y)  # Create complex number from the clicked point
            
            # Generate the Julia set for the clicked point
            J_fractal = julia(c, max_iter, J_xmin, J_xmax, J_ymin, J_ymax, width, height)
            
            # Update the Julia plot
            ax2.cla()  # Clear the previous Julia plot
            cax2 = ax2.imshow(J_fractal, extent=(J_xmin, J_xmax, J_ymin, J_ymax), cmap='hot', origin='lower')
            ax2.set_title(f'Julia Set for c = {c:.2f}')
            ax2.set_xlabel('Real Part')
            ax2.set_ylabel('Imaginary Part')       
        
            # Colorbar for Julia set
            plt.colorbar(cax2, ax=ax2)
            plt.draw()  # Refresh the figure


# Connect the click event to the update function
fig.canvas.mpl_connect('button_press_event', update_julia)

# Show the plots
plt.show()