def characterize_dataset(model, sequences, entity2unique, entity2same,
unique_text, nnlens):
predictions = model.predict(sequences)
t = AnnoyIndex(
len(predictions[0]),
metric='euclidean') # Length of item vector that will be indexed
t.set_seed(123)
for i in range(len(predictions)):
# print(predictions[i])
v = predictions[i]
t.add_item(i, v)
t.build(100) # 100 trees
for nnlen in nnlens:
print("Characteristics at neighborhood length:" + str(nnlen))
pos_distances = []
neg_distances = []
match = 0
no_match = 0
for key in entity2same:
index = entity2unique[key]
nearest = t.get_nns_by_vector(predictions[index], nnlen)
nearest_text = set([unique_text[i] for i in nearest])
expected_text = set(entity2same[key])
overlap = expected_text.intersection(nearest_text)
m = len(overlap)
match += m
# since we asked for only x nearest neighbors, and we get at most x-1 neighbors that are not the same as key (!)
# make sure we adjust our estimate of no match appropriately
no_match += min(len(expected_text), nnlen - 1) - m
# annoy has this annoying habit of returning the queried item back as a nearest neighbor. Remove it.
if key in nearest_text:
nearest_text.remove(key)
# sample only the negatives that are true negatives
# that is, they are not in the expected set - sampling only 'semi-hard negatives is not defined here'
pos = expected_text
neg = nearest_text - expected_text
for i in pos:
dist_pos = t.get_distance(index, entity2unique[i])
pos_distances.append(dist_pos)
for i in neg:
dist_neg = t.get_distance(index, entity2unique[i])
neg_distances.append(dist_neg)
recall = match / (match + no_match)
print("mean positive distance:" + str(statistics.mean(pos_distances)))
print("stdev positive distance:" +
str(statistics.stdev(pos_distances)))
print("max positive distance:" + str(max(pos_distances)))
print("mean neg distance:" + str(statistics.mean(neg_distances)))
print("stdev neg distance:" + str(statistics.stdev(neg_distances)))
print("max neg distance:" + str(max(neg_distances)))
print("recall:" + str(recall))
def _get_knn_graph_annoy(X,
n_neighbors=5,
dist_metric='euclidean',
random_seed=0):
'''
Build k-nearest-neighbor graph
Return edge list and nearest neighbor matrix
'''
try:
from annoy import AnnoyIndex
except ImportError:
raise ImportError('Please install the package "annoy". '
'Alternatively, set `knn_method=\'umap\'.')
npc = X.shape[1]
ncell = X.shape[0]
annoy_index = AnnoyIndex(npc, metric=dist_metric)
annoy_index.set_seed(random_seed)
for i in range(ncell):
annoy_index.add_item(i, list(X[i, :]))
annoy_index.build(10) # 10 trees
knn = []
knn_dists = []
for iCell in range(ncell):
neighbors, dists = annoy_index.get_nns_by_item(iCell,
n_neighbors + 1,
include_distances=True)
knn.append(neighbors[1:])
knn_dists.append(dists[1:])
knn = np.array(knn, dtype=int)
knn_dists = np.array(knn_dists)
return knn, knn_dists
def annoy_build(df, id, metric='euclidean'):
m = AnnoyIndex(VECTOR_SIZE, metric=metric)
m.set_seed(42)
for _, row in df.iterrows():
m.add_item(row[id], row['vectors'])
m.build(TREE_QUERIES)
return m
def find_candidates_udf(u_factor):
from annoy import AnnoyIndex # must import here !
u = AnnoyIndex(rank, 'dot')
u.set_seed(random_seed)
u.load(SparkFiles.get(
tree_ann_path)) # tree_ann_path must be absolute path
return u.get_nns_by_vector(u_factor,
n=nns,
search_k=-1,
include_distances=False)
def generate_semi_hard_triplets_from_ANN(model, sequences, entity2unique,
entity2same, unique_text, test):
predictions = model.predict(sequences)
t = AnnoyIndex(
len(predictions[0]),
metric='euclidean') # Length of item vector that will be indexed
t.set_seed(123)
for i in range(len(predictions)):
# print(predictions[i])
v = predictions[i]
t.add_item(i, v)
t.build(100) # 100 trees
triplets = {}
triplets['anchor'] = []
triplets['positive'] = []
triplets['negative'] = []
if test:
NNlen = TEST_NEIGHBOR_LEN
else:
NNlen = TRAIN_NEIGHBOR_LEN
for key in entity2same:
index = entity2unique[key]
expected_text = set(entity2same[key])
expected_ids = [entity2unique[i] for i in expected_text]
for positive in expected_text:
k = entity2unique[positive]
nearest = t.get_nns_by_vector(predictions[k], NNlen)
dist_k = t.get_distance(index, k)
semi_hards = []
for n in nearest:
if n == index or n in expected_ids or n == k:
continue
n_dist = t.get_distance(index, n)
if n_dist > dist_k:
semi_hards.append(unique_text[n])
# shuffle(semi_hards)
# semi_hards = semi_hards[0:20]
for i in semi_hards:
triplets['anchor'].append(key)
triplets['positive'].append(unique_text[k])
triplets['negative'].append(i)
return triplets
def generate_extra_pair_basis(basis,
X,
n_neighbors,
tree: AnnoyIndex,
distance='euclidean',
verbose=True):
'''Generate pairs that connects the extra set of data to the fitted basis.
'''
npr, dimp = X.shape
assert (
basis is not None or tree is not None
), "If the annoyindex is not cached, the original dataset must be provided."
# Build the tree again if not cached
if tree is None:
n, dim = basis.shape
assert dimp == dim, "The dimension of the original dataset is different from the new one's."
tree = AnnoyIndex(dim, metric=distance)
if _RANDOM_STATE is not None:
tree.set_seed(_RANDOM_STATE)
for i in range(n):
tree.add_item(i, basis[i, :])
tree.build(20)
else:
n = tree.get_n_items()
n_neighbors_extra = min(n_neighbors + 50, n - 1)
nbrs = np.zeros((npr, n_neighbors_extra), dtype=np.int32)
knn_distances = np.empty((npr, n_neighbors_extra), dtype=np.float32)
for i in range(npr):
nbrs[i, :], knn_distances[i, :] = tree.get_nns_by_vector(
X[i, :], n_neighbors_extra, include_distances=True)
print_verbose("Found nearest neighbor", verbose)
# sig = np.maximum(np.mean(knn_distances[:, 3:6], axis=1), 1e-10)
# print_verbose("Calculated sigma", verbose)
# Debug
# print_verbose(f"Sigma is of the scale of {sig.shape}", verbose)
# print_verbose(f"KNN dist is of shape scale of {knn_distances.shape}", verbose)
# print_verbose(f"nbrs max: {nbrs.max()}", verbose)
# scaling the distances is not possible since we don't always track the basis
# scaled_dist = scale_dist(knn_distances, sig, nbrs)
print_verbose("Found scaled dist", verbose)
pair_neighbors = sample_neighbors_pair_basis(n, X, knn_distances, nbrs,
n_neighbors)
return pair_neighbors
def load_index(path_index: PathType,
meta_d: Dict) \
-> AnnoyIndex:
""" We rely on ANNOY's usage of mmap to be fast loading
(fast enough that we can load it on every single call)
"""
n_dim = meta_d['n_dim']
metric = meta_d['metric']
u = AnnoyIndex(
n_dim,
metric=metric,
)
u.load(str(path_index))
u.set_seed(SEED)
return u
def test_seeding(self):
f = 10
X = numpy.random.rand(1000, f)
Y = numpy.random.rand(50, f)
indexes = []
for i in range(2):
index = AnnoyIndex(f, 'angular')
index.set_seed(42)
for j in range(X.shape[0]):
index.add_item(j, X[j])
index.build(10)
indexes.append(index)
for k in range(Y.shape[0]):
self.assertEquals(indexes[0].get_nns_by_vector(Y[k], 100),
indexes[1].get_nns_by_vector(Y[k], 100))
def test_seeding(self):
f = 10
X = numpy.random.rand(1000, f)
Y = numpy.random.rand(50, f)
indexes = []
for i in range(2):
index = AnnoyIndex(f)
index.set_seed(42)
for j in range(X.shape[0]):
index.add_item(j, X[j])
index.build(10)
indexes.append(index)
for k in range(Y.shape[0]):
self.assertEquals(indexes[0].get_nns_by_vector(Y[k], 100),
indexes[1].get_nns_by_vector(Y[k], 100))
def generate_pair(X,
n_neighbors,
n_MN,
n_FP,
distance='euclidean',
verbose=True):
'''Generate pairs for the dataset.
'''
n, dim = X.shape
# sample more neighbors than needed
n_neighbors_extra = min(n_neighbors + 50, n - 1)
tree = AnnoyIndex(dim, metric=distance)
if _RANDOM_STATE is not None:
tree.set_seed(_RANDOM_STATE)
for i in range(n):
tree.add_item(i, X[i, :])
tree.build(20)
option = distance_to_option(distance=distance)
nbrs = np.zeros((n, n_neighbors_extra), dtype=np.int32)
knn_distances = np.empty((n, n_neighbors_extra), dtype=np.float32)
for i in range(n):
nbrs_ = tree.get_nns_by_item(i, n_neighbors_extra + 1)
nbrs[i, :] = nbrs_[1:]
for j in range(n_neighbors_extra):
knn_distances[i, j] = tree.get_distance(i, nbrs[i, j])
print_verbose("Found nearest neighbor", verbose)
sig = np.maximum(np.mean(knn_distances[:, 3:6], axis=1), 1e-10)
print_verbose("Calculated sigma", verbose)
scaled_dist = scale_dist(knn_distances, sig, nbrs)
print_verbose("Found scaled dist", verbose)
pair_neighbors = sample_neighbors_pair(X, scaled_dist, nbrs, n_neighbors)
if _RANDOM_STATE is None:
pair_MN = sample_MN_pair(X, n_MN, option)
pair_FP = sample_FP_pair(X, pair_neighbors, n_neighbors, n_FP)
else:
pair_MN = sample_MN_pair_deterministic(X, n_MN, _RANDOM_STATE, option)
pair_FP = sample_FP_pair_deterministic(X, pair_neighbors, n_neighbors,
n_FP, _RANDOM_STATE)
return pair_neighbors, pair_MN, pair_FP, tree
def annoy_train(spark, dirname, rank, regParam, n_trees, random_seed):
# Load model
model = ALSModel.load(f'{dirname}/{rank}_{regParam}_model')
# get item factors
item_factors = model.itemFactors
item_factors, annoy_index_map = convert_annoy_index(item_factors)
# train annoy model
tree = AnnoyIndex(rank, 'dot')
for item in tqdm(item_factors.collect()):
tree.add_item(item.annoy_id, item.features)
tree.set_seed(random_seed)
# build the tree
# num of trees: higher n_trees gives higher precision
tree.build(n_trees)
# save annoy model and index map
tree.save(f'{dirname}_{rank}_{regParam}_tree.ann')
annoy_index_map.write.parquet(f'{dirname}_{rank}_{regParam}_annoy_index_map.parquet')
def predict_similar_movies(
review_vectors: pd.DataFrame,
parameters: Dict
) -> pd.DataFrame:
# 近似最近傍探索モデルを初期化
vector_size = review_vectors.iat[0, 1].size
annoy_index = AnnoyIndex(vector_size, parameters["similarity_metrics"])
annoy_index.set_seed(parameters["random_seed"])
# TODO ログ
print(f"review size: {len(review_vectors)}")
# インデックスの構築
idx2movie = {}
for i, row in enumerate(review_vectors.itertuples()):
idx2movie[i] = row.movie_id
annoy_index.add_item(i, row.vector)
# TODO ログ
if i % 10 == 0:
print(f"{i}番目のインデックスを構築完了")
annoy_index.build(parameters["n_tree"])
# 類似映画トップNを予測
similar_movies = {}
for j in range(len(review_vectors)):
# 同じ映画が最も近くなるため、1つずらす
similar_movies[idx2movie[j]] = annoy_index.get_nns_by_item(j, parameters["predict_num"] + 1)[1:]
if j % 10 == 0:
print(f"{j}番目の推論完了")
return pd.DataFrame({
"movie_id": similar_movies.keys(),
"similar_movie_ids": [[idx2movie[movie_id] for movie_id in movie_list] for movie_list in similar_movies.values()]
})
# 100%|############################| 402111/402111 [01:02<00:00, 6455.57it/s]
len(wv.vocab), len(wv[next(iter(wv.vocab))])
# (3000000, 300)
wv.vectors.shape
# (3000000, 300)
"""
>>> from annoy import AnnoyIndex
>>> num_words, num_dimensions = wv.vectors.shape # <1>
>>> index = AnnoyIndex(num_dimensions)
"""
from annoy import AnnoyIndex
num_words, num_dimensions = wv.vectors.shape # <1>
index = AnnoyIndex(num_dimensions)
index.set_seed(1983)
"""
>>> from tqdm import tqdm # <1>
>>> for i, word in enumerate(tqdm(wv.index2word)): # <2>
... index.add_item(i, wv[word])
22%|#######▏ | 649297/3000000 [00:26<01:35, 24587.52it/s]
<1> `tqdm()` takes an iterable and returns an iterable (like `enumerate()`) and inserts code in your loop to display a progress bar
<2> `.index2word` is an unsorted list of all 3M tokens in your vocabulary, equivalent to a map of the integer indexes (0-2999999) to tokens ('</s>' to 'snowcapped_Caucasus').
"""
from tqdm import tqdm
for i, word in enumerate(tqdm(wv.index2word)):
index.add_item(i, wv[word])
def test_seed(self):
i = AnnoyIndex(10, 'angular')
i.load('test/test.tree')
i.set_seed(42)
class AnnoyDictionary(object):
def __init__(self,
dict_size,
key_width,
new_value_shift_coefficient=0.1,
batch_size=100,
key_error_threshold=0.01):
self.max_size = dict_size
self.curr_size = 0
self.new_value_shift_coefficient = new_value_shift_coefficient
self.index = AnnoyIndex(key_width, metric='euclidean')
self.index.set_seed(1)
self.embeddings = np.zeros((dict_size, key_width))
self.values = np.zeros(dict_size)
self.lru_timestamps = np.zeros(dict_size)
self.current_timestamp = 0.0
# keys that are in this distance will be considered as the same key
self.key_error_threshold = key_error_threshold
self.initial_update_size = batch_size
self.min_update_size = self.initial_update_size
self.key_dimension = key_width
self.value_dimension = 1
self._reset_buffer()
self.built_capacity = 0
def add(self, keys, values):
# Adds new embeddings and values to the dictionary
indices = []
indices_to_remove = []
for i in range(keys.shape[0]):
index = self._lookup_key_index(keys[i])
if index:
# update existing value
self.values[index] += self.new_value_shift_coefficient * (
values[i] - self.values[index])
self.lru_timestamps[index] = self.current_timestamp
indices_to_remove.append(i)
else:
# add new
if self.curr_size >= self.max_size:
# find the LRU entry
index = np.argmin(self.lru_timestamps)
else:
index = self.curr_size
self.curr_size += 1
self.lru_timestamps[index] = self.current_timestamp
indices.append(index)
for i in reversed(indices_to_remove):
keys = np.delete(keys, i, 0)
values = np.delete(values, i, 0)
self.buffered_keys = np.vstack((self.buffered_keys, keys))
self.buffered_values = np.vstack((self.buffered_values, values))
self.buffered_indices = self.buffered_indices + indices
if len(self.buffered_indices) >= self.min_update_size:
self.min_update_size = max(self.initial_update_size,
int(self.curr_size * 0.02))
self._rebuild_index()
self.current_timestamp += 1
# Returns the stored embeddings and values of the closest embeddings
def query(self, keys, k):
if not self.has_enough_entries(k):
# this will only happen when the DND is not yet populated with enough entries, which is only during heatup
# these values won't be used and therefore they are meaningless
return [0.0], [0.0], [0]
_, indices = self._get_k_nearest_neighbors_indices(keys, k)
embeddings = []
values = []
for ind in indices:
self.lru_timestamps[ind] = self.current_timestamp
embeddings.append(self.embeddings[ind])
values.append(self.values[ind])
self.current_timestamp += 1
return embeddings, values, indices
def has_enough_entries(self, k):
return self.curr_size > k and (self.built_capacity > k)
def _get_k_nearest_neighbors_indices(self, keys, k):
distances = []
indices = []
for key in keys:
index, distance = self.index.get_nns_by_vector(
key, k, include_distances=True)
distances.append(distance)
indices.append(index)
return distances, indices
def _rebuild_index(self):
self.index.unbuild()
self.embeddings[self.buffered_indices] = self.buffered_keys
self.values[self.buffered_indices] = np.squeeze(self.buffered_values)
for idx, key in zip(self.buffered_indices, self.buffered_keys):
self.index.add_item(idx, key)
self._reset_buffer()
self.index.build(50)
self.built_capacity = self.curr_size
def _reset_buffer(self):
self.buffered_keys = np.zeros((0, self.key_dimension))
self.buffered_values = np.zeros((0, self.value_dimension))
self.buffered_indices = []
def _lookup_key_index(self, key):
distance, index = self._get_k_nearest_neighbors_indices([key], 1)
if distance != [[]] and distance[0][0] <= self.key_error_threshold:
return index
return None
class Annoy(KNNIndex):
VALID_METRICS = [
"cosine",
"euclidean",
"manhattan",
"hamming",
"dot",
"l1",
"l2",
"taxicab",
]
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.__data = None
def build(self, data, k):
from annoy import AnnoyIndex
N = data.shape[0]
annoy_metric = self.metric
annoy_aliases = {
"cosine": "angular",
"l1": "manhattan",
"l2": "euclidean",
"taxicab": "manhattan",
}
if annoy_metric in annoy_aliases:
annoy_metric = annoy_aliases[annoy_metric]
self.index = AnnoyIndex(data.shape[1], annoy_metric)
if self.random_state:
self.index.set_seed(self.random_state)
for i in range(N):
self.index.add_item(i, data[i])
# Number of trees. FIt-SNE uses 50 by default.
self.index.build(50)
# Return the nearest neighbors in the training set
distances = np.zeros((N, k))
indices = np.zeros((N, k)).astype(int)
def getnns(i):
# Annoy returns the query point itself as the first element
indices_i, distances_i = self.index.get_nns_by_item(
i, k + 1, include_distances=True
)
indices[i] = indices_i[1:]
distances[i] = distances_i[1:]
if self.n_jobs == 1:
for i in range(N):
getnns(i)
else:
from joblib import Parallel, delayed
Parallel(n_jobs=self.n_jobs, require="sharedmem")(
delayed(getnns)(i) for i in range(N)
)
return indices, distances
def query(self, query, k):
N = query.shape[0]
distances = np.zeros((N, k))
indices = np.zeros((N, k)).astype(int)
def getnns(v):
# Annoy returns the query point itself as the first element
indices_i, distances_i = self.index.get_nns_by_vector(
v, k + 1, include_distances=True
)
indices[i] = indices_i[1:]
distances[i] = distances_i[1:]
if self.n_jobs == 1:
for i in range(N):
getnns(query[i])
else:
from joblib import Parallel, delayed
Parallel(n_jobs=self.n_jobs, require="sharedmem")(
delayed(getnns)(query[i]) for i in range(N)
)
return indices, distances
log.debug(f'df_click shape: {df_click.shape}')
log.debug(f'{df_click.head()}')
# 得到每个文章id对应的词向量
article_vec_map = word2vec(df_click, 'user_id', 'click_article_id',
model_path)
f = open(w2v_file, 'wb')
# 将得到的词向量 保存至文件中
pickle.dump(article_vec_map, f)
f.close()
# 说白了就是先将加载进来的vector进行相似临近计算，然后生成一个树形结构的索引，这样查找速度会变得很快，只不过会牺牲一定的近似精度。
# 将 embedding 建立索引
article_index = AnnoyIndex(
256, 'angular') #metric='angular'表示使用 angular（余弦）距离度量来计算簇和哈希。
article_index.set_seed(2020)
##加载article_id和向量映射，添加到annoyIndex
for article_id, emb in tqdm(article_vec_map.items()):
article_index.add_item(article_id, emb)
# tree_num设置为100，在内存允许的情况下，越大越好
article_index.build(100)
user_item_ = df_click.groupby('user_id')['click_article_id'].agg(
lambda x: list(x)).reset_index()
user_item_dict = dict(
zip(user_item_['user_id'], user_item_['click_article_id']))
# 召回
n_split = max_threads
all_users = df_query['user_id'].unique()
shuffle(all_users)
class Annoy_Dict(LRU_KNN_ANNOY):
def __init__(self, config):
super(Annoy_Dict, self).__init__(config)
self.config = config
self.key_dim = self.config.knn_key_dim
self.index = AnnoyIndex(self.key_dim, metric='euclidean')
self.index.set_seed(123)
self.initial_update_size = self.config.knn_dict_update_step
self.min_update_size = self.initial_update_size
self.cached_embs = []
self.cached_vals = []
self.cached_terminals = []
self.cached_embs_next = []
self.cached_indices = []
self.build_capacity = 0
def _nn(self, keys, k):
assert np.ndim(keys) == 2
dists = []
inds = []
for key in keys:
ind, dist = self.index.get_nns_by_vector(key,
k,
include_distances=True)
dists.append(dist)
inds.append(ind)
return dists, inds
def _insert(self, keys, values, terminal, keys_next, indices):
self.cached_embs = self.cached_embs + keys
self.cached_vals = self.cached_vals + values
self.cached_terminals = self.cached_terminals + terminal
self.cached_embs_next = self.cached_embs_next + keys_next
self.cached_indices = self.cached_indices + indices
if len(self.cached_indices) >= self.min_update_size:
# self.min_update_size = max(self.initial_update_size, self.curr_capacity * 0.02)
self._update_index()
def _update_index(self):
self.index.unbuild()
for i, ind in enumerate(self.cached_indices):
new_emb = self.cached_embs[i]
new_val = self.cached_vals[i]
new_t = self.cached_terminals[i]
new_emb_next = self.cached_embs_next[i]
self.embs[ind] = new_emb
self.values[ind] = new_val
self.terminal[ind] = new_t
self.embs_next[ind] = new_emb_next
self.index.add_item(ind, new_emb)
self.cached_embs = []
self.cached_vals = []
self.cached_terminals = []
self.cached_embs_next = []
self.cached_indices = []
self.index.build(50)
self.build_capacity = self.curr_capacity
def _rebuild(self):
self.index.unbuild()
for ind, emb in enumerate(self.embs[:self.curr_capacity]):
self.index.add_item(ind, emb)
self.index.build(50)
self.build_capacity = self.curr_capacity
def queryable(self, k):
return (LRU_KNN_ANNOY.queryable(self, k) and (self.build_capacity > k))
@property
def capacity_(self):
# print("self.index.get_n_items: ", self.index.get_n_items())
return self.index.get_n_items()
def get_knn_graph(X,
k=5,
dist_metric='euclidean',
approx=False,
return_edges=True,
random_seed=0):
'''
Build k-nearest-neighbor graph
Return edge list and nearest neighbor matrix
'''
t0 = time.time()
if approx:
try:
from annoy import AnnoyIndex
except:
approx = False
print(
'Could not find library "annoy" for approx. nearest neighbor search'
)
if approx:
#print('Using approximate nearest neighbor search')
if dist_metric == 'cosine':
dist_metric = 'angular'
npc = X.shape[1]
ncell = X.shape[0]
annoy_index = AnnoyIndex(npc, metric=dist_metric)
annoy_index.set_seed(random_seed)
for i in range(ncell):
annoy_index.add_item(i, list(X[i, :]))
annoy_index.build(10) # 10 trees
knn = []
for iCell in range(ncell):
knn.append(annoy_index.get_nns_by_item(iCell, k + 1)[1:])
knn = np.array(knn, dtype=int)
else:
#print('Using sklearn NearestNeighbors')
if dist_metric == 'cosine':
nbrs = NearestNeighbors(n_neighbors=k,
metric=dist_metric,
algorithm='brute').fit(X)
else:
nbrs = NearestNeighbors(n_neighbors=k, metric=dist_metric).fit(X)
knn = nbrs.kneighbors(return_distance=False)
if return_edges:
links = set([])
for i in range(knn.shape[0]):
for j in knn[i, :]:
links.add(tuple(sorted((i, j))))
t_elapse = time.time() - t0
#print('kNN graph built in %.3f sec' %(t_elapse))
return links, knn
return knn
class alpha_KNN:
def __init__(self,
capacity,
key_dimension,
delta=0.001,
alpha=0.1,
batch_size=1000):
self.capacity = capacity
self.curr_capacity = 0
self.delta = delta
self.alpha = 0.001
self.embeddings = np.zeros((capacity, key_dimension))
self.values = np.zeros(capacity)
self.weights = np.zeros(capacity)
from annoy import AnnoyIndex
self.index = AnnoyIndex(key_dimension, metric='euclidean')
self.index.set_seed(123)
self.min_update_size = batch_size
self.cached_keys = []
self.cached_values = []
self.cached_indices = []
self.built_capacity = 0
def _nn(self, keys, k):
dists = []
inds = []
for key in keys:
ind, dist = self.index.get_nns_by_vector(key + [1.0],
k,
include_distances=True)
dists.append(dist)
inds.append(ind)
return dists, inds
def _insert(self, keys, values, indices):
self.cached_keys = self.cached_keys + keys
self.cached_values = self.cached_values + values
self.cached_indices = self.cached_indices + indices
if len(self.cached_indices) >= self.min_update_size:
self._rebuild_index()
def _rebuild_index(self):
self.index.unbuild()
for i, ind in enumerate(self.cached_indices):
new_key = self.cached_keys[i]
new_value = self.cached_values[i]
self.embeddings[ind] = new_key
self.values[ind] = new_value
self.weights[ind] = new_weight
self.index.add_item(ind, new_key + [new_weight])
self.cached_keys = []
self.cached_values = []
self.cached_indices = []
self.index.build(50)
self.built_capacity = self.curr_capacity
def queryable(self, k):
return (self.built_capacity > k)
# Returns the stored embeddings and values of the closest embeddings
def query(self, keys, k):
_, indices = self._nn(keys, k)
embs = []
values = []
weights = []
for ind in indices:
embs.append(self.embeddings[ind])
values.append(self.values[ind])
weights.append(self.weights[ind])
return embs, values, weights
# Adds new embeddings (and values) to the dictionary
def add(self, keys, values):
if self.queryable(5):
dists, inds = self._nn(keys, k=5)
for ind, dist in enumerate(dists):
for i, d in enumerate(dist):
index = inds[ind][i]
self.weights[index] *= (1 - self.alpha)
indices, keys_, values_ = [], [], []
for i, _ in enumerate(keys):
if self.curr_capacity >= self.capacity:
# find the LRU entry
index = np.argmin(self.weights)
else:
index = self.curr_capacity
self.curr_capacity += 1
self.weights[index] = 1.0
indices.append(index)
keys_.append(keys[i])
values_.append(values[i])
self._insert(keys_, values_, indices)
class annoy_dict(LRU_KNN):
def __init__(self,
capacity,
key_dimension,
delta=0.001,
alpha=0.1,
batch_size=100):
LRU_KNN.__init__(self, capacity, key_dimension, delta, alpha)
from annoy import AnnoyIndex
self.index = AnnoyIndex(key_dimension, metric='euclidean')
self.index.set_seed(123)
self.initial_update_size = batch_size
self.min_update_size = self.initial_update_size
self.cached_keys = []
self.cached_values = []
self.cached_indices = []
self.built_capacity = 0
def _nn(self, keys, k):
dists = []
inds = []
for key in keys:
ind, dist = self.index.get_nns_by_vector(key,
k,
include_distances=True)
dists.append(dist)
inds.append(ind)
return dists, inds
def _insert(self, keys, values, indices):
self.cached_keys = self.cached_keys + keys
self.cached_values = self.cached_values + values
self.cached_indices = self.cached_indices + indices
if len(self.cached_indices) >= self.min_update_size:
self.min_update_size = max(self.initial_update_size,
self.curr_capacity * 0.02)
self._update_index()
def _update_index(self):
self.index.unbuild()
for i, ind in enumerate(self.cached_indices):
new_key = self.cached_keys[i]
new_value = self.cached_values[i]
self.embeddings[ind] = new_key
self.values[ind] = new_value
self.index.add_item(ind, new_key)
self.cached_keys = []
self.cached_values = []
self.cached_indices = []
self.index.build(50)
self.built_capacity = self.curr_capacity
def _rebuild_index(self):
self.index.unbuild()
for ind, emb in enumerate(self.embeddings[:self.curr_capacity]):
self.index.add_item(ind, emb)
self.index.build(50)
self.built_capacity = self.curr_capacity
def queryable(self, k):
return (LRU_KNN.queryable(self, k) and (self.built_capacity > k))
class LRU_KNN:
def __init__(self, capacity, key_dim, value_dim, batch_size):
self.capacity = capacity
self.curr_capacity = 0
self.states = np.zeros((capacity, key_dim))
self.values = np.zeros((capacity, value_dim))
self.lru = np.zeros(capacity)
self.tm = 0.0
self.index = AnnoyIndex(key_dim, metric="euclidean")
self.index.set_seed(123)
self.initial_update_size = batch_size
self.min_update_size = self.initial_update_size
self.cached_states = []
self.cached_values = []
self.cached_indices = []
def nn(self, keys, k):
dists = []
inds = []
for key in keys:
ind, dist = self.index.get_nns_by_vector(key,
k,
include_distances=True)
dists.append(dist)
inds.append(ind)
return dists, inds
def query(self, keys, k):
_, indices = self.nn(keys, k)
states = []
values = []
for ind in indices:
self.lru[ind] = self.tm
states.append(self.states[ind])
values.append(self.values[ind])
self.tm += 0.001
return states, values
def _insert(self, keys, values, indices):
self.cached_states = self.cached_states + keys
self.cached_values = self.cached_values + values
self.cached_indices = self.cached_indices + indices
if len(self.cached_states) >= self.min_update_size:
self.min_update_size = max(self.initial_update_size,
self.curr_capacity * 0.02)
self._update_index()
def _update_index(self):
self.index.unbuild()
for i, ind in enumerate(self.cached_indices):
new_state = self.cached_states[i]
new_value = self.cached_values[i]
self.states[ind] = new_state
self.values[ind] = new_value
self.index.add_item(ind, new_state)
self.cached_states = []
self.cached_values = []
self.cached_indices = []
self.index.build(50)
self.built_capacity = self.curr_capacity
def _rebuild_index(self):
self.index.unbuild()
for ind, state in enumerate(self.states[:self.curr_capacity]):
self.index.add_item(ind, state)
self.index.build(50)
self.built_capacity = self.curr_capacity
#!/usr/bin/env python
# encoding: utf-8
from annoy import AnnoyIndex
test_dims = [64]
for dim in test_dims:
a = AnnoyIndex(dim, 'angular')
d = AnnoyIndex(dim, 'dot')
e = AnnoyIndex(dim, 'euclidean')
a.set_seed(123)
d.set_seed(123)
e.set_seed(123)
vectors = open('item_vector.txt').readlines()
for index, vector in enumerate(vectors):
v = [float(x) for x in vector.split(',')]
a.add_item(index, v)
d.add_item(index, v)
e.add_item(index, v)
a.build(3)
a.save('points.angular.annoy.{}'.format(dim))
d.build(3)
d.save('points.dot.annoy.{}'.format(dim))
e.build(3)
e.save('points.euclidean.annoy.{}'.format(dim))
import numpy as np
from annoy import AnnoyIndex
X = np.random.rand(100000, 60)
Y = np.random.rand(500, 60)
annoy1 = AnnoyIndex(60)
annoy1.set_seed(100)
for i in range(X.shape[0]):
annoy1.add_item(i, X[i, :])
annoy1.build(10)
annoy2 = AnnoyIndex(60)
annoy2.set_seed(100)
for j in range(X.shape[0]):
annoy2.add_item(j, X[j, :])
annoy2.build(10)
result1 = []
result2 = []
for k in range(Y.shape[0]):
print "annoy1", annoy1.get_nns_by_vector(Y[k, :], 3)
result1 += annoy1.get_nns_by_vector(Y[k, :], 3)
print "annoy2", annoy2.get_nns_by_vector(Y[k, :], 3)
result2 += annoy2.get_nns_by_vector(Y[k, :], 3)
class Memory:
def __init__(self, capacity, state_dim, value_dim):
self.capacity = capacity
print("state_dim:", state_dim)
self.states = np.zeros((capacity, state_dim))
self.values = np.zeros((capacity, value_dim))
self.curr_capacity = 0
self.curr_ = 0
self.lru = np.zeros(capacity)
self.tm = 0
self.cached_states = []
self.cached_values = []
self.cached_indices = []
self.index = AnnoyIndex(state_dim)
self.index.set_seed(123)
self.update_size = 1
self.build_capacity = 0
def sample_knn_test(self, state, k):
inds, dists = self.index.get_nns_by_vector(state,
k,
include_distances=True)
self.tm += 0.01
self.lru[inds] = self.tm
return self.states[inds], self.values[inds], dists
def sample_knn(self, states, k):
dists = []
inds = []
for state in states:
ind, dist = self.index.get_nns_by_vector(state,
k,
include_distances=True)
inds.append(ind)
dists.append(dist)
# inds = np.reshape(np.array(inds), -1)
self.tm += 0.01
self.lru[inds] = self.tm
return self.states[inds], self.values[inds], dists
def sample(self, n_samples):
if self.curr_capacity < n_samples or n_samples == 0:
idx = np.random.choice(np.arange(len(self.states)),
n_samples,
replace=False)
else:
idx = np.random.choice(np.arange(self.curr_capacity),
n_samples,
replace=False)
self.tm += 0.01
self.lru[idx] = self.tm
embs = self.states[idx]
values = self.values[idx]
return embs, values
def add_knn(self, states, values):
self._add_knn(states, values)
def add_knn_lru(self, states, values):
self._add_knn(states, values, lru=True)
def add(self, states, values):
self._add(states, values)
def add_lru(self, states, values):
self._add(states, values, lru=True)
def add_rand(self, states, values):
self._add(states, values, rand=True)
def _insert(self, states, values, indices):
self.cached_states = self.cached_states + states
self.cached_values = self.cached_values + values
self.cached_indices = self.cached_indices + indices
if len(self.cached_states) >= self.update_size:
self._update_index()
def _update_index(self):
self.index.unbuild()
for i, ind in enumerate(self.cached_indices):
self.states[ind] = self.cached_states[i]
self.values[ind] = self.cached_values[i]
self.index.add_item(ind, self.cached_states[i])
self.index.build(50)
self.build_capacity = self.curr_capacity
self.cached_states = []
self.cached_values = []
self.cached_indices = []
def _rebuild_index(self):
self.index.unbuild()
for ind, state in enumerate(self.states[:self.curr_capacity]):
self.index.add_item(ind, state)
self.index.build(50)
self.build_capacity = self.curr_capacity
def _add_knn(self, states, values, lru=False):
# print(states)
indices = []
states_ = []
values_ = []
for i, _ in enumerate(states):
if lru:
if self.curr_capacity >= self.capacity:
ind = np.argmin(self.lru)
else:
ind = self.curr_capacity
self.curr_capacity += 1
else:
if self.curr_capacity >= self.capacity:
self.curr_ = (self.curr_ + 1) % self.capacity
ind = self.curr_
else:
ind = self.curr_capacity
self.curr_capacity += 1
self.lru[ind] = self.tm
indices.append(ind)
states_.append(states[i])
values_.append(values[i])
self._insert(states_, values_, indices)
def _add(self, states, values, rand=False, lru=False):
for i, state in enumerate(states):
if self.curr_capacity < self.capacity:
self.curr_ = (self.curr_ + 1) % self.capacity
# self.states[self.curr_] = state
# self.values[self.curr_] = values[i]
if self.curr_capacity < self.capacity:
self.curr_capacity += 1
else:
if lru:
self.curr_ = np.argmin(self.lru)
if rand:
self.curr_ = np.random.choice(np.arange(
self.curr_capacity),
1,
replace=False)
if not lru and not rand:
self.curr_ = (self.curr_ + 1) % self.capacity
self.states[self.curr_] = state
self.values[self.curr_] = values[i]
@property
def length(self):
# assert self.index.get_n_items() == self.curr_capacity
# return self.curr_capacity
return self.index.get_n_items()
def test_seed(self):
i = AnnoyIndex(10)
i.load('test/test.tree')
i.set_seed(42)
def generate_triplets_from_ANN(model, sequences, entity2unique, entity2same, unique_text, test):
predictions = model.predict(sequences)
t = AnnoyIndex(len(predictions[0]), metric='euclidean') # Length of item vector that will be indexed
t.set_seed(123)
for i in range(len(predictions)):
# print(predictions[i])
v = predictions[i]
t.add_item(i, v)
t.build(100) # 100 trees
match = 0
no_match = 0
ann_accuracy = 0
total = 0
triplets = {}
pos_distances = []
neg_distances = []
triplets['anchor'] = []
triplets['positive'] = []
triplets['negative'] = []
if test:
NNlen = TEST_NEIGHBOR_LEN
else:
NNlen = TRAIN_NEIGHBOR_LEN
for key in entity2same:
index = entity2unique[key]
nearest = t.get_nns_by_vector(predictions[index], NNlen)
nearest_text = set([unique_text[i] for i in nearest])
expected_text = set(entity2same[key])
# annoy has this annoying habit of returning the queried item back as a nearest neighbor. Remove it.
if key in nearest_text:
nearest_text.remove(key)
# print("query={} names = {} true_match = {}".format(unique_text[index], nearest_text, expected_text))
overlap = expected_text.intersection(nearest_text)
# collect up some statistics on how well we did on the match
m = len(overlap)
match += m
# since we asked for only x nearest neighbors, and we get at most x-1 neighbors that are not the same as key (!)
# make sure we adjust our estimate of no match appropriately
no_match += min(len(expected_text), NNlen - 1) - m
# sample only the negatives that are true negatives
# that is, they are not in the expected set - sampling only 'semi-hard negatives is not defined here'
# positives = expected_text - nearest_text
positives = overlap
negatives = nearest_text - expected_text
# print(key + str(expected_text) + str(nearest_text))
for i in negatives:
for j in positives:
dist_pos = t.get_distance(index, entity2unique[j])
pos_distances.append(dist_pos)
dist_neg = t.get_distance(index, entity2unique[i])
neg_distances.append(dist_neg)
if dist_pos < dist_neg:
ann_accuracy += 1
total += 1
# print(key + "|" + j + "|" + i)
# print(dist_pos)
# print(dist_neg)
for i in negatives:
for j in expected_text:
triplets['anchor'].append(key)
triplets['positive'].append(j)
triplets['negative'].append(i)
print("mean positive distance:" + str(statistics.mean(pos_distances)))
print("stdev positive distance:" + str(statistics.stdev(pos_distances)))
print("max positive distance:" + str(max(pos_distances)))
print("mean neg distance:" + str(statistics.mean(neg_distances)))
print("stdev neg distance:" + str(statistics.stdev(neg_distances)))
print("max neg distance:" + str(max(neg_distances)))
print("Accuracy in the ANN for triplets that obey the distance func:" + str(ann_accuracy / total))
obj = {}
obj['accuracy'] = ann_accuracy / total
obj['steps'] = 1
with open(output_file_name_for_hpo, 'w') as out:
json.dump(obj, out)
if test:
return match/(match + no_match)
else:
return triplets, match/(match + no_match)
class Annoy(KNNIndex):
VALID_METRICS = [
"cosine",
"euclidean",
"manhattan",
"hamming",
"dot",
"l1",
"l2",
"taxicab",
]
def build(self, data, k):
timer = utils.Timer(
f"Finding {k} nearest neighbors using Annoy approximate search using "
f"{self.metric} distance...",
verbose=self.verbose,
)
timer.__enter__()
from annoy import AnnoyIndex
N = data.shape[0]
annoy_metric = self.metric
annoy_aliases = {
"cosine": "angular",
"l1": "manhattan",
"l2": "euclidean",
"taxicab": "manhattan",
}
if annoy_metric in annoy_aliases:
annoy_metric = annoy_aliases[annoy_metric]
self.index = AnnoyIndex(data.shape[1], annoy_metric)
if self.random_state:
self.index.set_seed(self.random_state)
for i in range(N):
self.index.add_item(i, data[i])
# Number of trees. FIt-SNE uses 50 by default.
self.index.build(50)
# Return the nearest neighbors in the training set
distances = np.zeros((N, k))
indices = np.zeros((N, k)).astype(int)
def getnns(i):
# Annoy returns the query point itself as the first element
indices_i, distances_i = self.index.get_nns_by_item(
i, k + 1, include_distances=True)
indices[i] = indices_i[1:]
distances[i] = distances_i[1:]
if self.n_jobs == 1:
for i in range(N):
getnns(i)
else:
from joblib import Parallel, delayed
Parallel(n_jobs=self.n_jobs,
require="sharedmem")(delayed(getnns)(i) for i in range(N))
timer.__exit__()
return indices, distances
def query(self, query, k):
timer = utils.Timer(
f"Finding {k} nearest neighbors in existing embedding using Annoy "
f"approximate search...",
self.verbose,
)
timer.__enter__()
N = query.shape[0]
distances = np.zeros((N, k))
indices = np.zeros((N, k)).astype(int)
def getnns(i):
indices[i], distances[i] = self.index.get_nns_by_vector(
query[i], k, include_distances=True)
if self.n_jobs == 1:
for i in range(N):
getnns(i)
else:
from joblib import Parallel, delayed
Parallel(n_jobs=self.n_jobs,
require="sharedmem")(delayed(getnns)(i) for i in range(N))
timer.__exit__()
return indices, distances