title: Couple elements in numpy array
body: <p>I have 1-dimensional numpy array (arr0) with different values. 
  I want to create a new array of elements, where each element is a couple (indexes and/or values) of one element to its closest one, considering that the absolute value of the difference (distance) of the couple is lower than a set threshold.</p>
  
  <p>At each step (coupling) I would like to remove the elements already coupled.</p>
  
  <pre><code>arr0 = [40, 55, 190, 80, 175, 187] #My original 1D array
  threshold = 20 #Returns elements if "abs(el_1 - el_2)&lt;threshold"
  #For each couple found, the code should remove the couple from the array and then go on with the next couple
  result_indexes = [[0, 1], [2, 5]]
  result_value = [[40, 55], [190, 187]]
  </code></pre>