Method update

join/LSH/datasketch/minhash.py:123–153

Update this MinHash with a new value. The value will be hashed using the hash function specified by the `hashfunc` argument in the constructor. Args: b: The value to be hashed using the hash function specified. Example: To update with a new s

(self, b)

        return np.array(hashvalues, dtype=np.uint64)

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

        Args:
            b: The value to be hashed using the hash function specified.

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

            .. code-block:: python

                minhash = Minhash()
                minhash.update("new value".encode('utf-8'))

            We can also use a different hash function, for example, `pyfarmhash`:

            .. code-block:: python

                import farmhash
                def _hash_32(b):
                    return farmhash.hash32(b)
                minhash = MinHash(hashfunc=_hash_32)
                minhash.update("new value")
        '''
        hv = self.hashfunc(b)
        a, b = self.permutations
        phv = np.bitwise_and((a * hv + b) % _mersenne_prime, _max_hash)
        self.hashvalues = np.minimum(phv, self.hashvalues)

    def update_batch(self, b):
        '''Update this MinHash with new values.