计算多个点之间的总距离

Question

如何使用循环计算列表中多个点之间的距离。

def create_list(x_range,y_range, locations):
  generated_list = []
  for x in range(locations):
    x_range = random.randint(-300,300)
    y_range = random.randint(-300,300)
    generated_list.append([x_range, y_range])
  return generated_list

上面创建了一个随机列表，我需要使用以下代码计算所有点返回起点的总距离：

def calculate_distance(starting_x, starting_y, destination_x, destination_y):
    distance = math.hypot(destination_x - starting_x, destination_y - starting_y)  # calculates Euclidean distance (straight-line) distance between two points
    return distance

这里我需要使用上面的函数循环计算所有点之间的距离，我将如何使用循环计算所有点之间的距离

Answer 1

您可以从(x, y) 的配对列表中

• 使用itertools.permutations 获取此列表中的排列。这是一个有 3 个点的示例，通过指定长度为 2，您得到了 6 个排列。

  values  = [(2, 1), (0, 3), (3, 2)]
  
  perm = [((2, 1), (0, 3)),   ((2, 1), (3, 2)),   ((0, 3), (2, 1)), 
          ((0, 3), (3, 2)),   ((3, 2), (2, 1)),   ((3, 2), (0, 3))]
  

• 用积分拨打您的calculate_distance

  p1 = (1,2)
  p2 = (2,3)
  dist = calculate_distance(*p1, *p2) #or calculate_distance(p1[0], p1[1], p2[0], p2[1])
  

使用所有这些

values = create_list(300, 300, 3)
for p1, p2 in permutations(values, r=2):
    dist = calculate_distance(*p1, *p2)
    print(p1, p2, dist)

总结它们都在循环中添加一个值来做total+=dist，或者使用sum，它接受一个可迭代和缩短

values = create_list(300, 300, 3)
total = sum(calculate_distance(*p1, *p2) for p1, p2 in permutations(values, r=2))

---

使用循环

仅对连续点求和

# Way 1 : d(a,b) + d(b,c) + d(c,d) + d(d,e) + d(e,a)
total = calculate_distance(*values[-1], *values[0])  # between  last and first
for i in range(len(values) - 1):
    total += calculate_distance(*values[i], *values[i + 1])
print(total)

对所有点的组合求和

# Way 2: d(a,b) + d(a,c) + d(a,d) + d(a,e) + d(b,c) + d(b,d) + d(b,e) + d(c,d) + d(c,e) + d(d,e)
total = 0
for p1 in values:
    for p2 in values:
        if p1 != p2:
            total += calculate_distance(*p1, *p2)
print(total)

Answer 2

import math

def calculate_distance(x1, y1, x2, y2):
    distance = math.hypot(x2 - x1, y2 - y1)
    return distance


def total_dist(ml):  # ml is a list of pairs of x,y points
    n = len(ml)
    total = 0.0
    for i in range (n):
        x1 = ml[i][0]
        y1 = ml[i][1]
        if i < n-1:
            x2 = ml[i+1][0]
            y2 = ml[i+1][1]
        else:
            x2 = ml[0][0]
            y2 = ml[0][1]
        dist = calculate_distance(x1,y1,x2,y2)
        total += dist
    return total

# main program
copy_list = [[110, -260], [284, -152], [-197, -167], [-253, 295], [-89, 26], [-165, 43], [-84, 148], [-188, 38], [201, 191], [232, 251]]
print total_dist(copy_list)