找到边界圆

Question

我的代码中的逻辑不是绝对的。我尝试通过将直径端点作为 1）距原点最远的点和 2）距 (1) 最远的点来找到边界圆的中心坐标和半径。 但这并不能在所有情况下给我实际的结果。 请不要介意缩进（我使用制表符并复制了我的代码。）

from tkinter import *

class point2D:
    def __init__(self, x=0, y=0):
        self.__x = x
        self.__y = y
    
    def x(self):
        return self.__x
    
    def y(self):
        return self.__y
    
    def setx(self, x):
        self.__x = x
    
    def sety(self, y):
        self.__y = y
    
    def __str__(self):
        return f"({self.__x}, {self.__y})"
    
    def distance(self, other):
        return ((self.__x-other.__x)**2 + (self.__y-other.__y)**2) ** 0.5

class box:
    def __init__(self):
        root = Tk()
        root.title("Bounding Circle")
        width, height = 600, 600
        root.geometry(f"{width}x{height}")
        
        self.canvas = Canvas(root, width=width, height=height, bg="white")
        self.canvas.pack()
        self.canvas.bind("<Button-1>", self.addpoint)
        
        self.origin = point2D()
        
        self.points = []
        
        root.mainloop()
    
    def addpoint(self, event):
        radius = 5
        self.canvas.create_oval(event.x - radius, event.y - radius,
        event.x + radius, event.y + radius, fill = "black")
        self.points.append(point2D(event.x, event.y))
        self.getboundingcircle()
    
    def getboundingcircle(self):
        if len(self.points) == (1 or 0):
            return
        #Finding the point farthest from origin (0,0 in canvas)
        d, start = self.points[0].distance(self.origin), 0
        for i in range(1, len(self.points)):
            x = self.points[i].distance(self.origin)
            if x > d:
                d = x
                start = i
        #Finding the point farthest from points[start]
        d, end = 0, 0
        for i in range(len(self.points)):
            if i == start:
                continue
            x = self.points[i].distance(self.points[start])
            if x > d:
                d = x
                end = i
        
        center_x = (self.points[start].x() + self. points[end].x()) / 2
        center_y = (self.points[start].y() + self. points[end].y()) / 2
        radius = self.points[start].distance(self.points[end]) / 2
        
        self.canvas.delete("circle")
        self.canvas.create_oval(center_x - radius, center_y - radius,
        center_x + radius, center_y + radius, outline = "red", tags = "circle")

box()

Answer 1

我认为修改盒子类中的

getboundingcircle

函数可能会达到你想要的效果。我不太明白这是否是预期的行为，但这是一种可能的行为。

你应该在开始时导入数学：

from tkinter import *
import math

然后替换你当前的函数：

def getboundingcircle(self):
    if len(self.points) < 2:
        return

    # Find the two farthest points
    max_dist = 0
    start, end = 0, 1  # Initialize start and end

    for i in range(len(self.points)):
        for j in range(i + 1, len(self.points)):
            dist = self.points[i].distance(self.points[j])
            if dist > max_dist:
                max_dist = dist
                start = i
                end = j

    center_x = (self.points[start].x() + self.points[end].x()) / 2
    center_y = (self.points[start].y() + self.points[end].y()) / 2
    radius = self.points[start].distance(self.points[end]) / 2

    self.canvas.delete("circle")
    self.canvas.create_oval(center_x - radius, center_y - radius,
                           center_x + radius, center_y + radius, 
                           outline="red", tags="circle")