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 subtest_result_order(self, nh):
d = 128
nq = 10
nb = 200
(_, xb, xq) = make_binary_dataset(d, 0, nb, nq)
nbit = 10
if nh == 0:
index = faiss.IndexBinaryHash(d, nbit)
else:
index = faiss.IndexBinaryMultiHash(d, nh, nbit)
index.add(xb)
index.nflip = 5
k = 10
Do, Io = index.search(xq, k)
self.assertTrue(np.all(Do[:, 1:] >= Do[:, :-1]))
def test_replicas(self):
d = 32
nq = 100
nb = 200
(_, xb, xq) = make_binary_dataset(d, 0, nb, nq)
index_ref = faiss.IndexBinaryFlat(d)
index_ref.add(xb)
Dref, Iref = index_ref.search(xq, 10)
# there is a OpenMP bug in this configuration, so disable threading
if sys.platform == "darwin" and "Clang 12" in sys.version:
nthreads = faiss.omp_get_max_threads()
faiss.omp_set_num_threads(1)
else:
nthreads = None
nrep = 5
index = faiss.IndexBinaryReplicas()
for _i in range(nrep):
sub_idx = faiss.IndexBinaryFlat(d)
sub_idx.add(xb)
index.addIndex(sub_idx)
D, I = index.search(xq, 10)
self.assertTrue((Dref == D).all())
self.assertTrue((Iref == I).all())
index2 = faiss.IndexBinaryReplicas()
for _i in range(nrep):
sub_idx = faiss.IndexBinaryFlat(d)
index2.addIndex(sub_idx)
index2.add(xb)
D2, I2 = index2.search(xq, 10)
if nthreads is not None:
faiss.omp_set_num_threads(nthreads)
self.assertTrue((Dref == D2).all())
self.assertTrue((Iref == I2).all())
def test_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)
radius = 55
Lref, Dref, Iref = index_ref.range_search(xq, radius)
print("nb res: ", Lref[-1])
nfound = []
ndis = []
for nh in 1, 3, 5:
index = faiss.IndexBinaryMultiHash(d, nh, 10)
index.add(xb)
# index.display()
stats = faiss.cvar.indexBinaryHash_stats
index.nflip = 2
stats.reset()
Lnew, Dnew, Inew = index.range_search(xq, radius)
for i in range(nq):
ref = Iref[Lref[i]:Lref[i + 1]]
new = Inew[Lnew[i]:Lnew[i + 1]]
snew = set(new)
# no duplicates
self.assertTrue(len(new) == len(snew))
# subset of real results
self.assertTrue(snew <= set(ref))
nfound.append(Lnew[-1])
ndis.append(stats.ndis)
print('nfound=', nfound)
print('ndis=', ndis)
nfound = np.array(nfound)
# self.assertTrue(nfound[-1] == Lref[-1])
self.assertTrue(np.all(nfound[1:] >= nfound[:-1]))