"""
Interface and plugin getter for LSH algorithm hash generation functors.
"""
import abc
import numpy as np
from smqtk_core import Configurable, Pluggable
[docs]class LshFunctor (Configurable, Pluggable):
"""
Locality-sensitive hashing functor interface.
The aim of such a function is to be able to generate hash codes
(bit-vectors) such that similar items map to the same or similar hashes
with a high probability. In other words, it aims to maximize hash collision
for similar items.
**Building Models**
Some hash functions want to build a model based on some training set of
descriptors. Due to the non-standard nature of algorithm training and model
building, please refer to the specific implementation for further
information on whether model training is needed and how it is accomplished.
"""
def __call__(self, descriptor: np.ndarray) -> np.ndarray:
return self.get_hash(descriptor)
[docs] @abc.abstractmethod
def get_hash(self, descriptor: np.ndarray) -> np.ndarray:
"""
Get the locality-sensitive hash code for the input descriptor.
:param descriptor: Descriptor vector we should generate the hash of.
:return: Generated bit-vector as a numpy array of booleans.
"""