列表中两点之间的距离公式 [英] Distance formula between two points in a list

问题描述

我需要列出一个已创建的列表，找到最接近的两个点并将其打印出来.如何比较列表中的每个点?

I need to take a list I have created and find the closest two points and print them out. How can I go about comparing each point in the list?

不需要绘图或任何东西，只需比较点并在列表中找到最接近的两个点即可.

There isn't any need to plot or anything, just compare the points and find the closest two in the list.

import math # 'math' needed for 'sqrt'

# Distance function
def distance(xi,xii,yi,yii):
    sq1 = (xi-xii)*(xi-xii)
    sq2 = (yi-yii)*(yi-yii)
    return math.sqrt(sq1 + sq2)

# Run through input and reorder in [(x, y), (x,y) ...] format
oInput = ["9.5 7.5", "10.2 19.1", "9.7 10.2"] # Original input list (entered by spacing the two points).
mInput = [] # Manipulated list
fList = [] # Final list
for o in oInput:
    mInput = o.split()
    x,y = float(mInput[0]), float(mInput[1])
    fList += [(x, y)] # outputs [(9.5, 7.5), (10.2, 19.1), (9.7, 10.2)]

推荐答案

使用两个(x, y)元组作为参数来重写distance()函数更方便:

It is more convenient to rewrite your distance() function to take two (x, y) tuples as parameters:

def distance(p0, p1):
    return math.sqrt((p0[0] - p1[0])**2 + (p0[1] - p1[1])**2)

现在，您要遍历列表fList中的所有对点.函数iterools.combinations()用于此目的很方便:

Now you want to iterate over all pairs of points from your list fList. The function iterools.combinations() is handy for this purpose:

min_distance = distance(fList[0], fList[1])
for p0, p1 in itertools.combinations(fList, 2):
    min_distance = min(min_distance, distance(p0, p1))

另一种方法是定义distance()以接受单个参数中的成对点

An alternative is to define distance() to accept the pair of points in a single parameter

def distance(points):
    p0, p1 = points
    return math.sqrt((p0[0] - p1[0])**2 + (p0[1] - p1[1])**2)

，然后将key参数用于内置的min()函数:

and use the key parameter to the built-in min() function:

min_pair = min(itertools.combinations(fList, 2), key=distance)
min_distance = distance(min_pair)

这篇关于列表中两点之间的距离公式的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！