class_docstr: Implements locality-sensitive hashing for low-dimensional euclidean space.
  
  
  Allows to efficiently find neighbours of a point. Provides 2 guarantees:
  
  -   Difference between coordinates of points not returned by :meth:`nearby`
      and input point is larger than ``radius``.
  -   Difference between coordinates of points returned by :meth:`nearby` and
      input point is smaller than 2 ``radius``.
  
  Example:
  
      >>> radius = 1
      >>> lsh = LSH(radius)
      >>> a = torch.tensor([-0.51, -0.51]) # hash(a)=(-1,-1)
      >>> b = torch.tensor([-0.49, -0.49]) # hash(a)=(0,0)
      >>> c = torch.tensor([1.0, 1.0]) # hash(b)=(1,1)
      >>> lsh.add('a', a)
      >>> lsh.add('b', b)
      >>> lsh.add('c', c)
      >>> # even though c is within 2radius of a
      >>> lsh.nearby('a') # doctest: +SKIP
      {'b'}
      >>> lsh.nearby('b') # doctest: +SKIP
      {'a', 'c'}
      >>> lsh.remove('b')
      >>> lsh.nearby('a') # doctest: +SKIP
      set()
  
  
  :param float radius: Scaling parameter used in hash function. Determines the size of the neighbourhood.
docstr: Removes ``key`` and corresponding point from the hash.
  
  
  Raises :exc:`KeyError` if key is not in hash.
  
  
  :param key: key used to identify point.
docstr_tok: ["Removes","``","key","``","and","corresponding","point","from","the","hash",".","Raises",":","exc",":","`","KeyError","`","if","key","is","not","in","hash",".",":","param","key",":","key","used","to","identify","point","."]
code: def remove(self, key):
      """
      Removes ``key`` and corresponding point from the hash.
  
  
      Raises :exc:`KeyError` if key is not in hash.
  
  
      :param key: key used to identify point.
      """
      _hash = self._key_to_hash.pop(key)
      self._hash_to_key[_hash].remove(key)
  
file_path: pyro/pyro/contrib/tracking/hashing.py
imports: import heapq
  import itertools
  from collections import defaultdict
  from numbers import Number
  import torch
label_desc: Use image node_id 4 for calling the LSH obj's underlying member method code with example usage: obj.remove(key) without return types