points.py

import numpy as np
from PIL import Image, ImageDraw


class Points:
    def __init__(
        self, rs: np.ndarray = None, thetas: np.ndarray = None, num_points: int = 23
    ):
        self.num_points = num_points
        if rs is None:
            self.rs = np.random.uniform(0.0, 1.0, self.num_points)
        else:
            self.rs = rs
        if thetas is None:
            self.thetas = np.sort(np.random.uniform(0.0, 2 * np.pi, self.num_points))
        else:
            self.thetas = thetas
            self._sort()

    def mutate(self, mutation_rate: float = 0.1):
        for i in range(self.num_points):
            if np.random.rand() < mutation_rate:
                self.rs[i] = np.random.uniform(0.0, 1.0)
            if np.random.rand() < mutation_rate:
                self.thetas[i] = np.random.uniform(0.0, 2 * np.pi)
        # 角度でソート
        self._sort()

    def to_image(self, image_size: int = 256) -> Image.Image:
        """256x256の画像として可視化する関数."""
        img = Image.new("L", (image_size, image_size), 255)
        draw = ImageDraw.Draw(img)
        center = image_size // 2

        # 点が存在しうる範囲を白色の円で描画
        draw.ellipse(
            (
                center - (image_size // 2),
                center - (image_size // 2),
                center + (image_size // 2),
                center + (image_size // 2),
            ),
            outline=0,
        )

        for r, theta in zip(self.rs, self.thetas):
            x = center + r * (image_size // 2) * np.cos(theta)
            y = center + r * (image_size // 2) * np.sin(theta)
            draw.ellipse((x - 2, y - 2, x + 2, y + 2), fill=0)

        return img

    def _sort(self):
        indices = np.argsort(self.thetas)
        self.rs = self.rs[indices]
        self.thetas = self.thetas[indices]


def crossover(points1: Points, points2: Points) -> Points:
    """GAにおける交叉操作を行う関数."""
    num_points = points1.num_points
    crossover_point = np.random.randint(5, num_points - 6)

    new_rs = np.concatenate(
        (points1.rs[:crossover_point], points2.rs[crossover_point:])
    )
    new_thetas = np.concatenate(
        (points1.thetas[:crossover_point], points2.thetas[crossover_point:])
    )
    new_points = Points(rs=new_rs, thetas=new_thetas)
    return new_points


if __name__ == "__main__":
    p1 = Points()
    p2 = Points()
    p1.to_image().save("points1.png")
    p2.to_image().save("points2.png")
    child = crossover(p1, p2)
    child.to_image().save("child.png")