Exploring the World of Complex Fractals: Generating and Rendering Mandelbrot, Julia, and Burning Ship Sets using Python

Welcome to this tutorial on how to generate and render a Mandelbrot fractal using Python! The Mandelbrot fractal is a beautiful and complex mathematical object that has captivated the imaginations of mathematicians and computer scientists for decades. In this tutorial, we will guide you through the process of generating and rendering a Mandelbrot fractal using Python, and provide some mathematical background on what the Mandelbrot fractal is and how it can be modified to create other fractals.

Before we get started, let’s take a look at some of the mathematical background behind the Mandelbrot fractal. The Mandelbrot fractal is a type of complex fractal, which means that it is generated by iterating a complex function over a complex domain. The function that is used to generate the Mandelbrot fractal is the following:

z = z^2 + c

where z and c are complex numbers. The function is iterated over a range of complex numbers c, and for each value of c, the corresponding value of z is calculated using the equation above. If the absolute value of z remains bounded as the iterations continue, then the point c is said to be part of the Mandelbrot set. If the absolute value of z becomes unbounded, then the point c is said to be outside of the Mandelbrot set.

The Mandelbrot fractal is generated by coloring each point c according to whether it is part of the Mandelbrot set or not. Points that are part of the Mandelbrot set are typically colored black, while points that are outside of the set are colored based on the number of iterations it took for the absolute value of z to become unbounded. This results in a beautiful and intricate pattern known as the Mandelbrot fractal.

Now that we have a basic understanding of what the Mandelbrot fractal is, let’s move on to the process of generating and rendering it using Python. The first step in this process is to define a function that iterates the complex function over a range of complex numbers and returns a list of points that are part of the Mandelbrot set. Here is an example of how we might define such a function:

def mandelbrot(xmin, xmax, ymin, ymax, width, height, max_iter):
    x, y = np.ogrid[xmin:xmax:width*1j, ymin:ymax:height*1j]
    c = x + y * 1j
    z = c
    divtime = max_iter + np.zeros(z.shape, dtype=int)
    
    for i in range(max_iter):
        z = z**2 + c
        diverge = z*np.conj(z) > 2**2            # who is diverging
        div_now = diverge & (divtime==max_iter)  # who is diverging now
        divtime[div_now] = i                      # note when
        z[diverge] = 2                            # avoid diverging too much
    
    return divtime

This function takes as input the dimensions of the complex domain (xmin, xmax, ymin, ymax), the dimensions of the image (width, height), and the maximum number of iterations to perform (max_iter). It generates a grid of complex numbers c using the numpy library, and then iterates the complex function over each point in the grid.

If the absolute value of z becomes unbounded, the function marks the point c as diverging and notes the number of iterations it took to diverge. If the absolute value of z remains bounded, the point c is marked as part of the Mandelbrot set. The function returns a list of points that are part of the Mandelbrot set, where each point is represented by the number of iterations it took for the point to diverge (if it diverged) or by the maximum number of iterations (if it did not diverge).

With the Mandelbrot set generated, the next step is to render the fractal using Python. To do this, we can use the matplotlib library to plot the points of the Mandelbrot set on a 2D grid. Here is an example of how we might do this:

import matplotlib.pyplot as plt

# Generate the Mandelbrot set
mandel = mandelbrot(-2, 0.5, -1, 1, 500, 500, 20)

# Plot the Mandelbrot set
plt.imshow(mandel.T, cmap='Blues', extent=[-2, 0.5, -1, 1])
plt.show()

This code generates the Mandelbrot set using the mandelbrot function defined earlier, and then plots the points of the set using the imshow function of matplotlib. The cmap parameter specifies the color map to use, and the extent parameter specifies the dimensions of the plot.

We have now successfully generated and rendered a Mandelbrot fractal using Python. We hope that you have found this tutorial helpful and that you now have a better understanding of how to generate and render fractals using Python.

As we mentioned earlier, the Mandelbrot fractal is just one example of a complex fractal that can be generated by iterating a complex function over a complex domain. By modifying the function and the domain, we can create a wide variety of different fractals.

For example, we can create the Julia fractal by using the following function:

z = z^2 + c

where c is a fixed complex number. This function is iterated over a range of complex numbers z, and the resulting fractal is colored based on whether the points z are part of the Julia set or not. The Julia set is defined in a similar way to the Mandelbrot set, with points that remain bounded being considered part of the set and points that become unbounded being considered outside of the set.

Another example of a complex fractal is the Burning Ship fractal, which is generated using the following function:

z = z^2 + c

where c is a complex number and z is defined as follows:

z = (abs(real(z)) + abs(imag(z))*i)^2

This function is iterated over a range of complex numbers c, and the resulting fractal is colored based on whether the points c are part of the Burning Ship set or not. The Burning Ship set is defined in a similar way to the Mandelbrot and Julia sets, with points that remain bounded being considered part of the set and points that become unbounded being considered outside of the set.

By experimenting with different functions and domains, we can create a wide variety of different complex fractals using Python. We hope that this tutorial has given you a taste of the possibilities and that you will have fun exploring the world of complex fractals. Happy coding!