faiss/python/test_build_blocks.py
2017-02-24 08:37:57 -08:00

80 lines
1.9 KiB
Python

# Copyright (c) 2015-present, Facebook, Inc.
# All rights reserved.
#
# This source code is licensed under the CC-by-NC license found in the
# LICENSE file in the root directory of this source tree.
#! /usr/bin/env python2
import libfb.py.mkl # noqa
import numpy as np
from libfb import testutil
import faiss
class TestClustering(testutil.BaseFacebookTestCase):
def test_clustering(self):
d = 64
n = 1000
np.random.seed(123)
x = np.random.random(size=(n, d)).astype('float32')
km = faiss.Kmeans(d, 32, niter=10)
err32 = km.train(x)
# check that objective is decreasing
prev = 1e50
for o in km.obj:
self.assertGreater(prev, o)
prev = o
km = faiss.Kmeans(d, 64, niter=10)
err64 = km.train(x)
# check that 64 centroids give a lower quantization error than 32
self.assertGreater(err32, err64)
class TestPCA(testutil.BaseFacebookTestCase):
def test_pca(self):
d = 64
n = 1000
np.random.seed(123)
x = np.random.random(size=(n, d)).astype('float32')
pca = faiss.PCAMatrix(d, 10)
pca.train(x)
y = pca.apply_py(x)
# check that energy per component is decreasing
column_norm2 = (y**2).sum(0)
prev = 1e50
for o in column_norm2:
self.assertGreater(prev, o)
prev = o
class TestProductQuantizer(testutil.BaseFacebookTestCase):
def test_pq(self):
d = 64
n = 1000
cs = 4
np.random.seed(123)
x = np.random.random(size=(n, d)).astype('float32')
pq = faiss.ProductQuantizer(d, cs, 8)
pq.train(x)
codes = pq.compute_codes(x)
x2 = pq.decode(codes)
diff = ((x - x2)**2).sum()
# print "diff=", diff
# diff= 1807.98
self.assertGreater(2500, diff)