def train_preprocessor():
print "train preproc", preproc_str
d = xt.shape[1]
t0 = time.time()
if preproc_str.startswith('OPQ'):
fi = preproc_str[3:-1].split('_')
m = int(fi[0])
dout = int(fi[1]) if len(fi) == 2 else d
preproc = faiss.OPQMatrix(d, m, dout)
elif preproc_str.startswith('PCAR'):
dout = int(preproc_str[4:-1])
preproc = faiss.PCAMatrix(d, dout, 0, True)
else:
assert False
preproc.train(sanitize(xt[:1000000]))
print "preproc train done in %.3f s" % (time.time() - t0)
return preproc
def __init__(self, d):
d2 = 256
nlist = 100 # numCentroids
m = 8 # numQuantizers
coarse_quantizer = faiss.IndexFlatL2(d2)
sub_index = faiss.IndexIVFPQ(coarse_quantizer, d2, nlist, 16, 8)
pca_matrix = faiss.PCAMatrix(d, d2, 0, True)
self.index2 = faiss.IndexPreTransform(pca_matrix, sub_index)
sub_index.own_fields = True
coarse_quantizer.this.disown()
self.sub_index = sub_index
self.pca_matrix = pca_matrix
self.index2.nprobe = 10
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
def test_progressive_dim(self):
d = 32
n = 10000
k = 50
xt, _, _ = get_dataset_2(d, n, 0, 0)
# basic kmeans
kmeans = faiss.Kmeans(d, k, gpu=True)
kmeans.train(xt)
pca = faiss.PCAMatrix(d, d)
pca.train(xt)
xt_pca = pca.apply(xt)
# same test w/ Kmeans wrapper
kmeans2 = faiss.Kmeans(d, k, progressive_dim_steps=5, gpu=True)
kmeans2.train(xt_pca)
self.assertLess(kmeans2.obj[-1], kmeans.obj[-1])
def preprocess_features(npdata, pca):
"""Preprocess an array of features.
Args:
npdata (np.array N * ndim): features to preprocess
pca (int): dim of output
Returns:
np.array of dim N * pca: data PCA-reduced, whitened and L2-normalized
"""
nan_location = np.isnan(npdata)
inf_location = np.isinf(npdata)
if (not np.allclose(nan_location, 0)) or (not np.allclose(inf_location,
0)):
print('before_Astype_Feature NaN or Inf found. Nan count: ',
np.sum(nan_location), ' Inf count: ', np.sum(inf_location))
print(
'###################### break ##################################'
)
return npdata
_, ndim = npdata.shape
npdata = npdata.astype('float32')
nan_location = np.isnan(npdata)
inf_location = np.isinf(npdata)
if (not np.allclose(nan_location, 0)) or (not np.allclose(inf_location,
0)):
print('after_Astype_Feature NaN or Inf found. Nan count: ',
np.sum(nan_location), ' Inf count: ', np.sum(inf_location))
print(
'###################### break ##################################'
)
return npdata
# Apply PCA-whitening with Faiss
mat = faiss.PCAMatrix(ndim, pca, eigen_power=-0.5)
mat.train(npdata)
assert mat.is_trained
npdata = mat.apply_py(npdata)
# L2 normalization
row_sums = np.linalg.norm(npdata, axis=1)
npdata = npdata / row_sums[:, np.newaxis]
return npdata
def kmeans_cluster(x, n_clusters, verbose=False, pcaDim=-1):
"""
K-means clustering using faiss library
"""
assert x.dim() == 2
n, d = x.size()
X = x.numpy()
if pcaDim > 0:
if verbose: print(f'Applying PCA from {d}dimensions to {pcaDim}')
pca = faiss.PCAMatrix(d, pcaDim)
pca.train(X)
assert pca.is_trained
Xpca = pca.apply_py(X)
else:
Xpca = X
if verbose: print('Clustering 2-dim tensor of size {}'.format(X.shape))
kmeans = faiss.Kmeans(Xpca.shape[1], n_clusters, niter=20, verbose=verbose)
kmeans.train(Xpca)
D, I = kmeans.index.search(Xpca, 1)
return torch.LongTensor(I).squeeze()
def preprocess_features(npdata, pca=64):
"""Preprocess an array of features.
Args:
npdata (np.array N * ndim): features to preprocess
pca (int): dim of output
Returns:
np.array of dim N * pca: data PCA-reduced, whitened and L2-normalized
"""
_, ndim = npdata.shape
npdata = npdata.astype('float32')
# Apply PCA-whitening with Faiss
mat = faiss.PCAMatrix(ndim, pca, eigen_power=-0.5)
mat.train(npdata)
assert mat.is_trained
npdata = mat.apply_py(npdata)
# L2 normalization
row_sums = np.linalg.norm(npdata, axis=1)
npdata = npdata / row_sums[:, np.newaxis]
return npdata
def main():
parser = get_parser()
args = parser.parse_args()
print("Reading features")
x = np.load(args.data, mmap_mode="r")
print("Computing PCA")
pca = faiss.PCAMatrix(x.shape[-1], args.dim, args.eigen_power)
pca.train(x)
b = faiss.vector_to_array(pca.b)
A = faiss.vector_to_array(pca.A).reshape(pca.d_out, pca.d_in)
os.makedirs(args.output, exist_ok=True)
prefix = str(args.dim)
if args.eigen_power != 0:
prefix += f"_{args.eigen_power}"
np.save(osp.join(args.output, f"{prefix}_pca_A"), A.T)
np.save(osp.join(args.output, f"{prefix}_pca_b"), b)
def preprocess_features(x, d=256):
"""
Calculate PCA + Whitening + L2 normalization for each vector
Args:
x (ndarray): N x D, where N is number of vectors, D - dimensionality
d (int): number of output dimensions (how many principal components to use).
Returns:
transformed [N x d] matrix xt .
"""
n, orig_d = x.shape
pcaw = faiss.PCAMatrix(d_in=orig_d, d_out=d, eigen_power=-0.5, random_rotation=False)
pcaw.train(x)
assert pcaw.is_trained
print 'Performing PCA + whitening'
x = pcaw.apply_py(x)
print 'x.shape after PCA + whitening:', x.shape
l2normalization = faiss.NormalizationTransform(d, 2.0)
print 'Performing L2 normalization'
x = l2normalization.apply_py(x)
return x
def train(self, vecs: np.ndarray, *args, **kwargs) -> None:
import faiss
num_samples, num_dim = vecs.shape
assert self.output_dim <= num_samples, 'training PCA requires at least %d points, but %d was given' % (
self.output_dim, num_samples)
assert self.output_dim < num_dim, 'PCA output dimension should < data dimension, received (%d, %d)' % (
self.output_dim, num_dim)
pca = faiss.PCAMatrix(num_dim, self.output_dim)
self.mean = np.mean(vecs, axis=0) # 1 x 768
pca.train(vecs)
explained_variance_ratio = faiss.vector_to_array(
pca.eigenvalues)[:self.output_dim]
components = faiss.vector_to_array(pca.PCAMat).reshape(
[-1, num_dim])[:self.output_dim]
# permutate engive according to variance
opt_order = get_perm(explained_variance_ratio, self.num_locals)
comp_tmp = np.reshape(components[opt_order],
[self.output_dim, num_dim])
self.pca_components = np.transpose(comp_tmp) # 768 x 200
def main():
# setting up the visible GPU
os.environ['CUDA_VISIBLE_DEVICES'] = "1"
# evaluate on test datasets
dataset = "pet"
cfg = configdataset("pet_show_alldatabase", get_data_root())
vectore_dir = 'best_model/se101_gem/model_epoch1/show_result'
vecs = np.load(
os.path.join(vectore_dir, "pet_show_alldatabase_vecs_ep1_resize.npy"))
qvecs = np.load(
os.path.join(vectore_dir, "pet_show_alldatabase_qvecs_ep1_resize.npy"))
vecs = vecs.T
qvecs = qvecs.T
ori_dim = int(qvecs.shape[1])
out_dim = 256
# scores = np.dot(vecs, qvecs.T)
# ranks = np.argsort(-scores, axis=0)
# print(ranks.shape)
# compute_map_and_print(dataset, ranks, cfg['gnd_id'])
##PCA method for test
mat = faiss.PCAMatrix(ori_dim, out_dim)
print(ori_dim, vecs.shape)
mat.train(np.ascontiguousarray(vecs))
assert mat.is_trained
qvecs_pca = mat.apply_py(np.ascontiguousarray(qvecs))
vecs_pca = mat.apply_py(np.ascontiguousarray(vecs))
print(qvecs_pca.shape)
np.save(
os.path.join(vectore_dir,
"pet_show_alldatabase_vecs_ep1_resize_pca.npy"), vecs_pca)
np.save(
os.path.join(vectore_dir,
"pet_show_alldatabase_qvecs_ep1_resize_pca.npy"),
qvecs_pca)
def __init__(self,
filename,
name='RN',
normalize=False,
how_many=15000,
st='test',
indexes=None,
distance='l2',
preproc=None,
**kwargs):
super().__init__()
self.rn_feats = self.load_features(filename, how_many, indexes)
self.normalize = normalize
self.st = st
self.distance = distance
self.indexes = indexes
if normalize:
self.rn_feats = utils.normalized(self.rn_feats, 1)
self.name = name
self.preproc = preproc
if preproc == 'lsh':
lsh_nbits = orig_dims // 2 if 'lsh_nbits' not in kwargs else kwargs[
'lsh_nbits']
self.preproc_arg = lsh_nbits
self.index = build_lsh(self.rn_feats, self.get_identifier(),
lsh_nbits)
if preproc == 'pca':
orig_dims = self.rn_feats.shape[1]
pca_dims = orig_dims // 2 if 'pca_dims' not in kwargs else kwargs[
'pca_dims']
self.preproc_arg = pca_dims
mat = faiss.PCAMatrix(self.rn_feats.shape[1], pca_dims)
mat.train(self.rn_feats)
assert mat.is_trained
self.rn_feats = mat.apply_py(self.rn_feats)
assert self.rn_feats.shape[1] == pca_dims
print('PCA from {} to {}'.format(orig_dims, pca_dims))
def train_preprocessor(self, preproc_str_local, xt_local):
if not self.preproc_cachefile or not os.path.exists(
self.preproc_cachefile):
print("train preproc", preproc_str_local)
d = xt_local.shape[1]
t0 = time.time()
if preproc_str_local.startswith('OPQ'):
fi = preproc_str_local[3:].split('_')
m = int(fi[0])
dout = int(fi[1]) if len(fi) == 2 else d
preproc = faiss.OPQMatrix(d, m, dout)
elif preproc_str_local.startswith('PCAR'):
dout = int(preproc_str_local[4:-1])
preproc = faiss.PCAMatrix(d, dout, 0, True)
else:
assert False
preproc.train(indexfunctions.sanitize(xt_local[:100000000]))
print("preproc train done in %.3f s" % (time.time() - t0))
faiss.write_VectorTransform(preproc, self.preproc_cachefile)
else:
print("load preproc ", self.preproc_cachefile)
preproc = faiss.read_VectorTransform(self.preproc_cachefile)
return preproc
def train_pca(hidden_states, target=100, max_train_sample_size=None):
'''
Takes 2d array of hidden states.
Will train PCA to reduce second dimension from n to target
If max_train_sample_size is provided, a random sample of n from hidden states will be used to train.
Returns: pcamatrix and bias
'''
d1 = hidden_states.shape[1]
pca = faiss.PCAMatrix(d1, target)
if max_train_sample_size and hidden_states.shape[0] > max_train_sample_size:
rnd_indices = np.random.choice(len(hidden_states),
size=max_train_sample_size)
hidden_states_train = hidden_states[rnd_indices]
pca.train(np.array(hidden_states_train))
else:
pca.train(np.array(hidden_states))
bias = faiss.vector_to_array(pca.b)
pcamatrix = faiss.vector_to_array(pca.A).reshape(pca.d_out, pca.d_in)
return (pcamatrix, bias)
def index_patches(patches, pca_dims=64):
# settings for faiss:
num_lists, M, num_bits = 200, 16, 8
# assertions:
assert torch.is_tensor(patches) and patches.dim() == 2
assert type(pca_dims) == int and pca_dims > 0
if pca_dims > patches.size(1):
print('WARNING: Input dimension < %d. Using fewer PCA dimensions.' % pca_dims)
pca_dims = patches.size(1) - (patches.size(1) % M)
# construct faiss index:
quantizer = faiss.IndexFlatL2(pca_dims)
assert pca_dims % M == 0
sub_index = faiss.IndexIVFPQ(quantizer, pca_dims, num_lists, M, num_bits)
pca_matrix = faiss.PCAMatrix(patches.size(1), pca_dims, 0, True)
faiss_index = faiss.IndexPreTransform(pca_matrix, sub_index)
# train faiss index:
patches = patches.numpy()
faiss_index.train(patches)
faiss_index.add(patches)
return faiss_index, sub_index
yield res.get()
res = res_next
yield res.get()
fv3_dir = os.getenv('DDIR') + '/features/'
if 'train' in todo:
f = h5py.File(fv3_dir + 'f100m/block0.hdf5', 'r')
count = f['count'][0]
labels = f['all_labels'][:count]
features = f['all_feats'][:count]
pca = faiss.PCAMatrix(2048, 256, 0, True)
pca.train(features)
faiss.write_VectorTransform(pca, fv3_dir + 'PCAR256.vt')
if 'apply' in todo:
pca = faiss.read_VectorTransform(fv3_dir + 'PCAR256.vt')
def load_block(i):
f = h5py.File(fv3_dir + 'f100m/block%d.hdf5' % i, 'r')
count = f['count'][0]
# labels = f['all_labels'][:count]
features = f['all_feats'][:count]
return features
# one read thread, one PCA computation thread, and main thread writes result.
def preprocess_features(npdata, n_components=16, method='PCA', n_jobs=1):
"""Preprocess an array of features.
Args:
npdata (np.array N * ndim): features to preprocess
pca (int): dim of output
Returns:
np.array of dim N * pca: data PCA-reduced, whitened and L2-normalized
"""
_, ndim = npdata.shape
npdata = npdata.astype('float32')
# Apply PCA-whitening with Faiss
if method == 'PCA':
mat = faiss.PCAMatrix(ndim, n_components, eigen_power=-0.5)
mat.train(npdata)
assert mat.is_trained
npdata = mat.apply_py(npdata)
# Apply UMAP for dimensionality reduction
elif method == 'UMAP':
fit = UMAP(n_components=n_components, metric='cosine')
npdata = np.ascontiguousarray(fit.fit_transform(npdata))
# Apply T-SNE for dimensionality reduction
elif method == 'TSNE':
if n_components > 3:
X = sk_PCA().fit_transform(npdata)
PCAinit = X[:, :n_components] / np.std(X[:, 0]) * 0.0001
fit = TSNE(n_components=n_components, init=PCAinit, n_jobs=n_jobs)
npdata = np.ascontiguousarray(fit.fit_transform(npdata),
dtype='float32')
else:
fit = sk_TSNE(n_components=n_components,
metric='cosine',
n_jobs=n_jobs)
npdata = np.ascontiguousarray(fit.fit_transform(npdata))
# Apply adaptive T-SNE for dimensionality reduction
elif method == 'AdaptiveTSNE':
pca = sk_PCA().fit(npdata)
# Find all the eigenvectors that explain 95% of the variance
i = 0
s = 0
for j in range(len(pca.explained_variance_ratio_)):
s += pca.explained_variance_ratio_[j]
if s > 0.95:
i = j
# Prevent smaller than 8
if i < 8:
i = 8
break
# Fit and transform the data with the number of components that explain 95%
pca95_well = sk_PCA(n_components=i).fit_transform(npdata)
# Do a similarity measure with TSNE on the pca data
if n_components > 3:
PCAinit = pca95_well[:, :n_components] / np.std(
pca95_well[:, 0]) * 0.0001
fit = TSNE(n_components=n_components, init=PCAinit, n_jobs=n_jobs)
npdata = np.ascontiguousarray(fit.fit_transform(pca95_well))
else:
fit = sk_TSNE(n_components=n_components,
metric='cosine',
n_jobs=n_jobs)
npdata = np.ascontiguousarray(fit.fit_transform(pca95_well))
# L2 normalization
row_sums = np.linalg.norm(npdata, axis=1)
npdata = npdata / row_sums[:, np.newaxis]
return npdata
def test_mm(self):
# trouble with MKL+fbmake that appears only at runtime. Check it here
x = np.random.random(size=(100, 20)).astype('float32')
mat = faiss.PCAMatrix(20, 10)
mat.train(x)
mat.apply_py(x)
def run_pca(x, output_dimensionality):
mat = faiss.PCAMatrix(x.shape[1], output_dimensionality)
mat.train(x)
assert mat.is_trained
return mat.apply_py(x)
if train or pca:
train_subset = np.empty((n_train_subset, FEATURES_NUMBER), dtype=np.float32)
print("Adding {} train features for training".format(n_train_subset))
for label, features in label_features.items():
n_features = max(1, features.shape[0] // 5)
train_subset[subset_i:subset_i+n_features] = features[:n_features]
#for n_feature in range(n_features):
# index_dict[subset_i+n_feature] = int(label)
subset_i += n_features
if pca:
if os.path.exists(INDEX_FILENAME_PCA):
mat = faiss.read_VectorTransform(INDEX_FILENAME_PCA)
else:
mat = faiss.PCAMatrix (FEATURES_NUMBER, PCA_FEATURES)
print("PCA training... started")
mat.train(train_subset)
print("PCA training... finished")
faiss.write_VectorTransform(mat, INDEX_FILENAME_PCA)
if pca:
print("PCA transformation... started")
train_subset = mat.apply_py(train_subset) if pca else train_subset
print("PCA transformation... finished")
cpu_index = faiss.IndexFlatL2(PCA_FEATURES if pca else FEATURES_NUMBER)
#cpu_index = faiss.index_factory(PCA_FEATURES if pca else FEATURES_NUMBER, "IVF4096,Flat")
index = faiss.index_cpu_to_gpu(res, 0, cpu_index, co) if gpu else cpu_index#, co)
def main():
parser = get_parser()
args = parser.parse_args()
faiss_specs = parse_faiss_specs(args.faiss_specs)
print("Faiss Specs:", faiss_specs)
feat_path = osp.join(args.save_dir, "features")
if osp.exists(feat_path + ".npy"):
feats = np.load(feat_path + ".npy")
else:
generator, num = get_iterator(args)
iterator = generator()
feats = []
for f in tqdm.tqdm(iterator, total=num):
feats.append(f)
del iterator
del generator
feats = np.concatenate(feats)
print(feats.shape)
os.makedirs(args.save_dir, exist_ok=True)
# np.save(feat_path, feats)
gc.collect()
torch.cuda.empty_cache()
reload = False
for spec in faiss_specs:
print("Processing spec", spec)
if reload:
print("Reloading...")
del feats
gc.collect()
feats = np.load(feat_path + ".npy")
save_path = osp.join(args.save_dir, spec.spec_str)
os.makedirs(save_path, exist_ok=True)
d = feats.shape[-1]
x = feats
if spec.pca > 0:
print("Computing PCA")
pca = faiss.PCAMatrix(d, spec.pca)
pca.train(x)
d = spec.pca
b = faiss.vector_to_array(pca.b)
A = faiss.vector_to_array(pca.A).reshape(pca.d_out, pca.d_in)
np.save(osp.join(save_path, "pca_A"), A.T)
np.save(osp.join(save_path, "pca_b"), b)
print("Applying PCA")
x = pca.apply_py(x)
if spec.norm:
reload = spec.pca <= 0
print("Normalizing")
faiss.normalize_L2(x)
print("Computing kmeans")
kmeans = faiss.Kmeans(
d,
spec.n_clus,
niter=50,
verbose=True,
spherical=spec.sphere,
max_points_per_centroid=feats.shape[0],
gpu=True,
nredo=3,
)
kmeans.train(x)
np.save(osp.join(save_path, "centroids"), kmeans.centroids)
del kmeans
del x
gc.collect()
def run_pca(x, output_dimensionality):
x = c_f.to_numpy(x).astype(np.float32)
mat = faiss.PCAMatrix(x.shape[1], output_dimensionality)
mat.train(x)
assert mat.is_trained
return mat.apply_py(x)
author : h-j-13
time : 2018-6-20
ref : https://github.com/facebookresearch/faiss/wiki/Faiss-building-blocks:-clustering,-PCA,-quantization
"""
import numpy
import faiss
numpy.random.seed(13)
# 通过PCA将40维的向量缩减为10维
# =============测试数据=============
mt = numpy.random.rand(1000, 40).astype('float32')
print mt[0]
mat = faiss.PCAMatrix(40, 10) # 40维缩减为10维
mat.train(mt) # 训练模型
assert mat.is_trained
tr = mat.apply_py(mt)
# print this to show that the magnitude of tr's columns is decreasing
print tr[0]
# print (tr ** 2).sum(0)
# =============Python Console=============
# [7.7770239e-01 2.3754121e-01 8.2427853e-01 9.6574920e-01 9.7260112e-01
# 4.5344925e-01 6.0904247e-01 7.7552652e-01 6.4161336e-01 7.2201824e-01
# 3.5036523e-02 2.9844946e-01 5.8512490e-02 8.5706097e-01 3.7285402e-01
# 6.7984796e-01 2.5627995e-01 3.4758121e-01 9.4127702e-03 3.5833380e-01
# 9.4909418e-01 2.1789901e-01 3.1939137e-01 9.1777241e-01 3.1903666e-02
# 6.5084539e-02 6.2982899e-01 8.7381345e-01 8.7157320e-03 7.4657726e-01
# 8.1284118e-01 7.5717449e-02 6.5645534e-01 5.0926220e-01 4.7988340e-01
if args.nt_sample == 0:
xt_pca = xt[args.nt:args.nt + 10000]
xt = xt[:args.nt]
else:
xt_pca = xt[args.nt_sample:args.nt_sample + 10000]
rs = np.random.RandomState(args.seed)
idx = rs.choice(args.nt_sample, size=args.nt, replace=False)
xt = xt[idx]
xb = xb[:args.nb]
d = xb.shape[1]
if args.pcadim != -1:
print "training PCA: %d -> %d" % (d, args.pcadim)
pca = faiss.PCAMatrix(d, args.pcadim)
pca.train(sanitize(xt_pca))
xt = pca.apply_py(sanitize(xt))
xb = pca.apply_py(sanitize(xb))
d = xb.shape[1]
######################################################
# Run clustering
######################################################
index = faiss.IndexFlatL2(d)
if ngpu > 0:
print "moving index to GPU"