get the nearest nested list from a given nested list-CodePudding

So I have a 2 values [-82.819309,40.081296] and a list of multiple nested values like

[[-83.0347849999999, 39.945993],
 [-82.957851, 40.060118],
 [-82.994303, 40.013227],
 [-82.8265609999999, 39.9207779999999],
 [-82.9984709999999, 39.887616],
 ...]

Now I want to get the list from the nested list whose difference from the two values is the minimum. something like

>>> getmin([1,2], [[1,1],[1,4],[2,3],[3,2]]) 
[1,1]

Logic:

[1,2] - [1,1] = abs(1-1)   abs(2-1) -> 1
[1,2] - [1,4] = abs(1-1)   abs(2-4) -> 2
[1,2] - [2,3] = abs(1-2)   abs(2-3) -> 2
[1,2] - [3,2] = abs(1-3)   abs(2-2) -> 2

Is there a way to do this?

CodePudding user response：

You can use very simple code:

import numpy as np

mylist = [[-83.0347849999999, 39.945993],
 [-82.957851, 40.060118],
 [-82.994303, 40.013227],
 [-82.8265609999999, 39.9207779999999],
 [-82.9984709999999, 39.887616],
 ...]

def item_of_min_norm(target_coordinate):
    norms  = [np.linalg.norm(np.array(target_coordinate,float)-np.array(item,float), ord=1) for item in mylist]
    index_of_minimum = np.argmin(norms)
    minimum_item = mylist[index_of_minimum]
    return minimum_item


# Use the new function
closest_to_1_1 = item_of_min_norm([1.0,1.0])

However, if I can guess your use case correctly, you probably want to use a KDTree. See https://scikit-learn.org/stable/modules/generated/sklearn.neighbors.KDTree.html