def test_hash_and_multihash(self):
d = 128
nq = 100
nb = 2000
(_, xb, xq) = make_binary_dataset(d, 0, nb, nq)
index_ref = faiss.IndexBinaryFlat(d)
index_ref.add(xb)
k = 10
Dref, Iref = index_ref.search(xq, k)
nfound = {}
for nh in 0, 1, 3, 5:
for nbit in 4, 7:
if nh == 0:
index = faiss.IndexBinaryHash(d, nbit)
else:
index = faiss.IndexBinaryMultiHash(d, nh, nbit)
index.add(xb)
index.nflip = 2
Dnew, Inew = index.search(xq, k)
nf = 0
for i in range(nq):
ref = Iref[i]
new = Inew[i]
snew = set(new)
# no duplicates
self.assertTrue(len(new) == len(snew))
nf += len(set(ref) & snew)
print('nfound', nh, nbit, nf)
nfound[(nh, nbit)] = nf
self.assertGreater(nfound[(nh, 4)], nfound[(nh, 7)])
# test serialization
index2 = faiss.deserialize_index_binary(
faiss.serialize_index_binary(index))
D2, I2 = index2.search(xq, k)
np.testing.assert_array_equal(Inew, I2)
np.testing.assert_array_equal(Dnew, D2)
print('nfound=', nfound)
self.assertGreater(3, abs(nfound[(0, 7)] - nfound[(1, 7)]))
self.assertGreater(nfound[(3, 7)], nfound[(1, 7)])
self.assertGreater(nfound[(5, 7)], nfound[(3, 7)])
def __setstate__(self, data):
self.faiss_index = faiss.deserialize_index_binary(data)