从列表中访问元素？

Question

I am trying to calculate the distance between two lists so I can find the shortest distance between all coordinates.

Here is my code:

import random
import math
import copy

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
def nearest_neighbour_algorithm(selected_map):

  temp_map = copy.deepcopy(selected_map)
  optermised_map = [] # we setup an empty optimised list to fill up

  # get last element of temp_map to set as starting point, also removes it from temp_list 
  optermised_map.append(temp_map.pop()) # we set the first element of the temp_map and put it in optimised_map as the starting point and remove this element from the temp_map

  for x in range(len(temp_map)):
    nearest_value = 1000 
    neares_index = 0       
    for i in range(len(temp_map[x])):
      current_value = calculate_distance(*optermised_map[x], *temp_map[x])

I get an error at this part and im not sure why:

    for i in range(len(temp_map[x])):
      current_value = calculate_distance(*optermised_map[x], *temp_map[x])

I am trying to find the distance between points between these two lists and the error I get is that my list index is out of range where the for loop is

Answer 1

On the first iteration optermised_map would be length 1. This would likely cause the error because it's iterating over len(temp_map) which is likely more than 1. I think you may have wanted:

for i in range(len(optermised_map)):
  current_value = calculate_distance(*optermised_map[i], *temp_map[x])

Answer 2

Are the lengths of the lists the same? I could be wrong, but this sounds like a cosine similarity exercise to me. Check out this very simple exercise.

from scipy import spatial

dataSetI = [3, 45, 7, 2]
dataSetII = [2, 54, 13, 15]
result = 1 - spatial.distance.cosine(dataSetI, dataSetII)
result
# 0.97228425171235

dataSetI = [1, 2, 3, 10]
dataSetII = [2, 4, 6, 20]
result = 1 - spatial.distance.cosine(dataSetI, dataSetII)
result
# 1.0

dataSetI = [10, 200, 234, 500]
dataSetII = [45, 3, 19, 20]
result = 1 - spatial.distance.cosine(dataSetI, dataSetII)
result
# 0.4991255575740505

In the second iteration, we can see that the ratios of the numbers in the two lists are exactly the same, but the numbers are different. We focus in the ratios of the numbers.