Method update_batch

join/LSH/datasketch/minhash.py:155–175

Update this MinHash with new values. The values will be hashed using the hash function specified by the `hashfunc` argument in the constructor. Args: b (list): List of values to be hashed using the hash function specified. Example: To update

(self, b)

        self.hashvalues = np.minimum(phv, self.hashvalues)

    def update_batch(self, b):
        '''Update this MinHash with new values.
        The values will be hashed using the hash function specified by
        the `hashfunc` argument in the constructor.

        Args:
            b (list): List of values to be hashed using the hash function specified.

        Example:
            To update with new string values (using the default SHA1 hash
            function, which requires bytes as input):

            .. code-block:: python

                minhash = Minhash()
                minhash.update_batch([s.encode('utf-8') for s in ["token1", "token2"]])
        '''
        hv = np.array([self.hashfunc(_b) for _b in b], dtype=np.uint64)
        a, b = self.permutations
        phv = np.bitwise_and(((hv * np.tile(a, (len(hv), 1)).T).T + b) % _mersenne_prime, _max_hash)
        self.hashvalues = np.vstack([phv, self.hashvalues]).min(axis=0)

    def jaccard(self, other):
        '''Estimate the `Jaccard similarity`_ (resemblance) between the sets