faiss/faiss.py

250 lines
7.2 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
# sorry for putting this in the main Faiss directory. This is to avoid
# having to write from python import faiss
import numpy as np
import types
import sys
import pdb
try:
from swigfaiss_gpu import *
except ImportError as e:
if e.args[0] != 'ImportError: No module named swigfaiss_gpu':
# swigfaiss_gpu is there but failed to load: Warn user about it.
print >> sys.stderr, "Failed to load GPU Faiss: %s" % e.args[0]
print >> sys.stderr, "Faiss falling back to CPU-only."
from swigfaiss import *
##################################################################
# The functions below add or replace some methods for classes
# this is to be able to pass in numpy arrays directly
def replace_method(the_class, name, replacement):
orig_method = getattr(the_class, name)
if orig_method.__name__ == 'replacement_' + name:
# replacement was done in parent class
return
setattr(the_class, name + '_c', orig_method)
setattr(the_class, name, replacement)
def handle_Clustering():
def replacement_train(self, x, index):
assert x.flags.contiguous
n, d = x.shape
assert d == self.d
self.train_c(n, swig_ptr(x), index)
replace_method(Clustering, 'train', replacement_train)
handle_Clustering()
def handle_Index(the_class):
def replacement_add(self, x):
assert x.flags.contiguous
n, d = x.shape
assert d == self.d
self.add_c(n, swig_ptr(x))
def replacement_add_with_ids(self, x, ids):
n, d = x.shape
assert d == self.d
assert ids.shape == (n, )
self.add_with_ids_c(n, swig_ptr(x), swig_ptr(ids))
def replacement_train(self, x):
assert x.flags.contiguous
n, d = x.shape
assert d == self.d
self.train_c(n, swig_ptr(x))
def replacement_search(self, x, k):
assert x.flags.contiguous
n, d = x.shape
assert d == self.d
distances = np.empty((n, k), dtype=np.float32)
labels = np.empty((n, k), dtype=np.int64)
self.search_c(n, swig_ptr(x),
k, swig_ptr(distances),
swig_ptr(labels))
return distances, labels
replace_method(the_class, 'add', replacement_add)
replace_method(the_class, 'add_with_ids', replacement_add_with_ids)
replace_method(the_class, 'train', replacement_train)
replace_method(the_class, 'search', replacement_search)
def handle_VectorTransform(the_class):
def apply_method(self, x):
assert x.flags.contiguous
n, d = x.shape
assert d == self.d_in
y = np.empty((n, self.d_out), dtype=np.float32)
self.apply_noalloc(n, swig_ptr(x), swig_ptr(y))
return y
def replacement_vt_train(self, x):
assert x.flags.contiguous
n, d = x.shape
assert d == self.d_in
self.train_c(n, swig_ptr(x))
replace_method(the_class, 'train', replacement_vt_train)
# apply is reserved in Pyton...
the_class.apply_py = apply_method
def handle_AutoTuneCriterion(the_class):
def replacement_set_groundtruth(self, D, I):
if D:
assert I.shape == D.shape
self.nq, self.gt_nnn = I.shape
self.set_groundtruth_c(
self.gt_nnn, swig_ptr(D) if D else None, swig_ptr(I))
def replacement_evaluate(self, D, I):
assert I.shape == D.shape
assert I.shape == (self.nq, self.nnn)
return self.evaluate_c(swig_ptr(D), swig_ptr(I))
replace_method(the_class, 'set_groundtruth', replacement_set_groundtruth)
replace_method(the_class, 'evaluate', replacement_evaluate)
def handle_ParameterSpace(the_class):
def replacement_explore(self, index, xq, crit):
assert xq.shape == (crit.nq, index.d)
ops = OperatingPoints()
self.explore_c(index, crit.nq, swig_ptr(xq),
crit, ops)
return ops
replace_method(the_class, 'explore', replacement_explore)
this_module = sys.modules[__name__]
for symbol in dir(this_module):
obj = getattr(this_module, symbol)
# print symbol, isinstance(obj, (type, types.ClassType))
if isinstance(obj, (type, types.ClassType)):
the_class = obj
if issubclass(the_class, Index):
handle_Index(the_class)
if issubclass(the_class, VectorTransform):
handle_VectorTransform(the_class)
if issubclass(the_class, AutoTuneCriterion):
handle_AutoTuneCriterion(the_class)
if issubclass(the_class, ParameterSpace):
handle_ParameterSpace(the_class)
def vector_float_to_array(v):
a = np.empty(v.size(), dtype='float32')
memcpy(swig_ptr(a), v.data(), 4 * v.size())
return a
class Kmeans:
def __init__(self, d, k, niter=25, verbose=False):
self.d = d
self.k = k
self.cp = ClusteringParameters()
self.cp.niter = niter
self.cp.verbose = verbose
self.centroids = None
def train(self, x):
assert x.flags.contiguous
n, d = x.shape
assert d == self.d
clus = Clustering(d, self.k, self.cp)
self.index = IndexFlatL2(d)
clus.train(x, self.index)
centroids = vector_float_to_array(clus.centroids)
self.centroids = centroids.reshape(self.k, d)
self.obj = vector_float_to_array(clus.obj)
return self.obj[-1]
def assign(self, x):
assert self.centroids is not None, "should train before assigning"
index = IndexFlatL2(self.d)
index.add(self.centroids)
D, I = index.search(x, 1)
return D.ravel(), I.ravel()
def kmin(array, k):
""" return k smallest values of a float32 array """
I = np.zeros(k, dtype='int64')
D = np.zeros(k, dtype='float32')
ha = float_maxheap_array_t()
ha.ids = swig_ptr(I)
ha.val = swig_ptr(D)
ha.nh = 1
ha.k = k
ha.heapify()
ha.addn(array.size, swig_ptr(array))
ha.reorder()
return D, I
def kmax(array, k):
""" return k largest values of a float32 array """
I = np.zeros(k, dtype='int64')
D = np.zeros(k, dtype='float32')
ha = float_minheap_array_t()
ha.ids = swig_ptr(I)
ha.val = swig_ptr(D)
ha.nh = 1
ha.k = k
ha.heapify()
ha.addn(array.size, swig_ptr(array))
ha.reorder()
return D, I
def rand(n, seed=12345):
res = np.empty(n, dtype='float32')
float_rand(swig_ptr(res), n, seed)
return res
def lrand(n, seed=12345):
res = np.empty(n, dtype='int64')
long_rand(swig_ptr(res), n, seed)
return res
def randn(n, seed=12345):
res = np.empty(n, dtype='float32')
float_randn(swig_ptr(res), n, seed)
return res
def eval_intersection(I1, I2):
""" size of intersection between each line of two result tables"""
n = I1.shape[0]
assert I2.shape[0] == n
k1, k2 = I1.shape[1], I2.shape[1]
ninter = 0
for i in range(n):
ninter += ranklist_intersection_size(k1, swig_ptr(I1[i]), k2, swig_ptr(I2[i]))
return ninter
def normalize_L2(x):
fvec_renorm_L2(x.shape[1], x.shape[0], swig_ptr(x))