<divclass="line"><aname="l00006"></a><spanclass="lineno"> 6</span> <spanclass="comment"> * This source code is licensed under the CC-by-NC license found in the</span></div>
<divclass="line"><aname="l00007"></a><spanclass="lineno"> 7</span> <spanclass="comment"> * LICENSE file in the root directory of this source tree.</span></div>
<divclass="line"><aname="l00010"></a><spanclass="lineno"> 10</span> <spanclass="comment">// Copyright 2004-present Facebook. All Rights Reserved.</span></div>
<divclass="line"><aname="l00011"></a><spanclass="lineno"> 11</span> <spanclass="comment">// -*- c++ -*-</span></div>
<divclass="line"><aname="l00031"></a><spanclass="lineno"> 31</span> <spanclass="comment"> * In the inverted file, the quantizer (an Index instance) provides a</span></div>
<divclass="line"><aname="l00032"></a><spanclass="lineno"> 32</span> <spanclass="comment"> * quantization index for each vector to be added. The quantization</span></div>
<divclass="line"><aname="l00033"></a><spanclass="lineno"> 33</span> <spanclass="comment"> * index maps to a list (aka inverted list or posting list), where the</span></div>
<divclass="line"><aname="l00034"></a><spanclass="lineno"> 34</span> <spanclass="comment"> * id of the vector is then stored.</span></div>
<divclass="line"><aname="l00036"></a><spanclass="lineno"> 36</span> <spanclass="comment"> * At search time, the vector to be searched is also quantized, and</span></div>
<divclass="line"><aname="l00037"></a><spanclass="lineno"> 37</span> <spanclass="comment"> * only the list corresponding to the quantization index is</span></div>
<divclass="line"><aname="l00038"></a><spanclass="lineno"> 38</span> <spanclass="comment"> * searched. This speeds up the search by making it</span></div>
<divclass="line"><aname="l00039"></a><spanclass="lineno"> 39</span> <spanclass="comment"> * non-exhaustive. This can be relaxed using multi-probe search: a few</span></div>
<divclass="line"><aname="l00040"></a><spanclass="lineno"> 40</span> <spanclass="comment"> * (nprobe) quantization indices are selected and several inverted</span></div>
<divclass="line"><aname="l00041"></a><spanclass="lineno"> 41</span> <spanclass="comment"> * lists are visited.</span></div>
<divclass="line"><aname="l00043"></a><spanclass="lineno"> 43</span> <spanclass="comment"> * Sub-classes implement a post-filtering of the index that refines</span></div>
<divclass="line"><aname="l00044"></a><spanclass="lineno"> 44</span> <spanclass="comment"> * the distance estimation from the query to databse vectors.</span></div>
<divclass="line"><aname="l00047"></a><spanclass="lineno"><aclass="line"href="structfaiss_1_1IndexIVF.html#ab38fde4c923abefc4185eb7450b5b95b"> 47</a></span> <spanclass="keywordtype">size_t</span><aclass="code"href="structfaiss_1_1IndexIVF.html#ab38fde4c923abefc4185eb7450b5b95b">nlist</a>; <spanclass="comment">///< number of possible key values</span></div>
<divclass="line"><aname="l00048"></a><spanclass="lineno"><aclass="line"href="structfaiss_1_1IndexIVF.html#affed235eadf27a13d753ee4d33a1dc58"> 48</a></span> <spanclass="comment"></span><spanclass="keywordtype">size_t</span><aclass="code"href="structfaiss_1_1IndexIVF.html#affed235eadf27a13d753ee4d33a1dc58">nprobe</a>; <spanclass="comment">///< number of probes at query time</span></div>
<divclass="line"><aname="l00050"></a><spanclass="lineno"><aclass="line"href="structfaiss_1_1IndexIVF.html#a4b40cc7a70dff41196a3b8769586667a"> 50</a></span> <aclass="code"href="structfaiss_1_1Index.html">Index</a> * <aclass="code"href="structfaiss_1_1IndexIVF.html#a4b40cc7a70dff41196a3b8769586667a">quantizer</a>; <spanclass="comment">///< quantizer that maps vectors to inverted lists</span></div>
<divclass="line"><aname="l00051"></a><spanclass="lineno"><aclass="line"href="structfaiss_1_1IndexIVF.html#a23ee7f75f8be4472a17778f2b33875de"> 51</a></span> <spanclass="comment"></span><spanclass="keywordtype">bool</span><aclass="code"href="structfaiss_1_1IndexIVF.html#a23ee7f75f8be4472a17778f2b33875de">quantizer_trains_alone</a>; <spanclass="comment">///< just pass over the trainset to quantizer</span></div>
<divclass="line"><aname="l00052"></a><spanclass="lineno"><aclass="line"href="structfaiss_1_1IndexIVF.html#aed2e9757ad5f3c234fd8ad60175a2a73"> 52</a></span> <spanclass="comment"></span><spanclass="keywordtype">bool</span><aclass="code"href="structfaiss_1_1IndexIVF.html#aed2e9757ad5f3c234fd8ad60175a2a73">own_fields</a>; <spanclass="comment">///< whether object owns the quantizer</span></div>
<divclass="line"><aname="l00058"></a><spanclass="lineno"> 58</span> <spanclass="comment"> /// map for direct access to the elements. Enables reconstruct().</span></div>
<divclass="line"><aname="l00062"></a><spanclass="lineno"> 62</span> <spanclass="comment"> /** The Inverted file takes a quantizer (an Index) on input,</span></div>
<divclass="line"><aname="l00063"></a><spanclass="lineno"> 63</span> <spanclass="comment"> * which implements the function mapping a vector to a list</span></div>
<divclass="line"><aname="l00064"></a><spanclass="lineno"> 64</span> <spanclass="comment"> * identifier. The pointer is borrowed: the quantizer should not</span></div>
<divclass="line"><aname="l00065"></a><spanclass="lineno"> 65</span> <spanclass="comment"> * be deleted while the IndexIVF is in use.</span></div>
<divclass="line"><aname="l00072"></a><spanclass="lineno"> 72</span> <spanclass="comment"> /// Trains the quantizer and calls train_residual to train sub-quantizers</span></div>
<divclass="line"><aname="l00073"></a><spanclass="lineno"> 73</span> <spanclass="comment"></span><spanclass="keyword">virtual</span><spanclass="keywordtype">void</span><aclass="code"href="structfaiss_1_1IndexIVF.html#a7a1d5eec194db0977b2318c6ed6a2b86">train</a> (<aclass="code"href="structfaiss_1_1Index.html#a040c6aed1f224f3ea7bf58eebc0c31a4">idx_t</a> n, <spanclass="keyword">const</span><spanclass="keywordtype">float</span> *x) <spanclass="keyword">override</span>;</div>
<divclass="line"><aname="l00080"></a><spanclass="lineno"> 80</span> <spanclass="comment"> /// Sub-classes that encode the residuals can train their encoders here</span></div>
<divclass="line"><aname="l00081"></a><spanclass="lineno"> 81</span> <spanclass="comment"> /// does nothing by default</span></div>
<divclass="line"><aname="l00082"></a><spanclass="lineno"> 82</span> <spanclass="comment"></span><spanclass="keyword">virtual</span><spanclass="keywordtype">void</span><aclass="code"href="structfaiss_1_1IndexIVF.html#a567ef760fd09d09ce2ee4f4e6c2d7280">train_residual</a> (<aclass="code"href="structfaiss_1_1Index.html#a040c6aed1f224f3ea7bf58eebc0c31a4">idx_t</a> n, <spanclass="keyword">const</span><spanclass="keywordtype">float</span> *x);</div>
<divclass="line"><aname="l00084"></a><spanclass="lineno"> 84</span> <spanclass="comment"> /** moves the entries from another dataset to self. On output,</span></div>
<divclass="line"><aname="l00085"></a><spanclass="lineno"> 85</span> <spanclass="comment"> * other is empty. add_id is added to all moved ids (for</span></div>
<divclass="line"><aname="l00086"></a><spanclass="lineno"> 86</span> <spanclass="comment"> * sequential ids, this would be this->ntotal */</span></div>
<divclass="line"><aname="l00100"></a><spanclass="lineno"> 100</span> <spanclass="comment"> /// display some stats about the inverted lists</span></div>
<divclass="line"><aname="l00109"></a><spanclass="lineno"> 109</span> <spanclass="comment">/** Inverted file with stored vectors. Here the inverted file</span></div>
<divclass="line"><aname="l00110"></a><spanclass="lineno"> 110</span> <spanclass="comment"> * pre-selects the vectors to be searched, but they are not otherwise</span></div>
<divclass="line"><aname="l00114"></a><spanclass="lineno"> 114</span> <spanclass="comment"> /** Inverted list of original vectors. Each list is a nl * d</span></div>
<divclass="line"><aname="l00115"></a><spanclass="lineno"> 115</span> <spanclass="comment"> * matrix, where nl is the nb of vectors stored in the list. */</span></div>
<divclass="line"><aname="l00122"></a><spanclass="lineno"> 122</span> <spanclass="comment"> /** Return the typeName of the index (which includes main parameters */</span></div>
<divclass="line"><aname="l00126"></a><spanclass="lineno"> 126</span> <spanclass="comment"> /// same as add_with_ids, with precomputed coarse quantizer</span></div>
<divclass="line"><aname="l00127"></a><spanclass="lineno"> 127</span> <spanclass="comment"></span><spanclass="keywordtype">void</span><aclass="code"href="structfaiss_1_1IndexIVFFlat.html#aea729c3d8c70bdd93f8e413e834851a4">add_core</a> (<aclass="code"href="structfaiss_1_1Index.html#a040c6aed1f224f3ea7bf58eebc0c31a4">idx_t</a> n, <spanclass="keyword">const</span><spanclass="keywordtype">float</span> * x, <spanclass="keyword">const</span><spanclass="keywordtype">long</span> *xids,</div>
<divclass="line"><aname="l00143"></a><spanclass="lineno"> 143</span> <spanclass="comment"> /** copy a subset of the entries index to the other index</span></div>
<divclass="line"><aname="l00145"></a><spanclass="lineno"> 145</span> <spanclass="comment"> * if subset_type == 0: copies ids in [a1, a2)</span></div>
<divclass="line"><aname="l00146"></a><spanclass="lineno"> 146</span> <spanclass="comment"> * if subset_type == 1: copies ids if id % a1 == a2</span></div>
<divclass="line"><aname="l00156"></a><spanclass="lineno"> 156</span> <spanclass="comment"> /// Implementation of the search for the inner product metric</span></div>
<divclass="line"><aname="l00162"></a><spanclass="lineno"> 162</span> <spanclass="comment"> /// Implementation of the search for the L2 metric</span></div>
<divclass="ttc"id="structfaiss_1_1IndexIVFFlat_html_a9ca8cc3ca71ff91f1e5e2db3b8ead615"><divclass="ttname"><ahref="structfaiss_1_1IndexIVFFlat.html#a9ca8cc3ca71ff91f1e5e2db3b8ead615">faiss::IndexIVFFlat::search_knn_L2sqr</a></div><divclass="ttdeci">void search_knn_L2sqr(size_t nx, const float *x, const long *keys, float_maxheap_array_t *res) const </div><divclass="ttdoc">Implementation of the search for the L2 metric. </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8cpp_source.html#l00319">IndexIVF.cpp:319</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVF_html_affed235eadf27a13d753ee4d33a1dc58"><divclass="ttname"><ahref="structfaiss_1_1IndexIVF.html#affed235eadf27a13d753ee4d33a1dc58">faiss::IndexIVF::nprobe</a></div><divclass="ttdeci">size_t nprobe</div><divclass="ttdoc">number of probes at query time </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8h_source.html#l00048">IndexIVF.h:48</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVF_html_a23ee7f75f8be4472a17778f2b33875de"><divclass="ttname"><ahref="structfaiss_1_1IndexIVF.html#a23ee7f75f8be4472a17778f2b33875de">faiss::IndexIVF::quantizer_trains_alone</a></div><divclass="ttdeci">bool quantizer_trains_alone</div><divclass="ttdoc">just pass over the trainset to quantizer </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8h_source.html#l00051">IndexIVF.h:51</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVFFlat_html_a1d0a5285344c3302ba10bb79f4578a82"><divclass="ttname"><ahref="structfaiss_1_1IndexIVFFlat.html#a1d0a5285344c3302ba10bb79f4578a82">faiss::IndexIVFFlat::copy_subset_to</a></div><divclass="ttdeci">void copy_subset_to(IndexIVFFlat &other, int subset_type, long a1, long a2) const </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8cpp_source.html#l00441">IndexIVF.cpp:441</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVF_html_af16d325f5bef22b2e5f90ceea796e80d"><divclass="ttname"><ahref="structfaiss_1_1IndexIVF.html#af16d325f5bef22b2e5f90ceea796e80d">faiss::IndexIVF::ids</a></div><divclass="ttdeci">std::vector< std::vector< long >> ids</div><divclass="ttdoc">Inverted lists for indexes. </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8h_source.html#l00056">IndexIVF.h:56</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVF_html_a4b40cc7a70dff41196a3b8769586667a"><divclass="ttname"><ahref="structfaiss_1_1IndexIVF.html#a4b40cc7a70dff41196a3b8769586667a">faiss::IndexIVF::quantizer</a></div><divclass="ttdeci">Index * quantizer</div><divclass="ttdoc">quantizer that maps vectors to inverted lists </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8h_source.html#l00050">IndexIVF.h:50</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVF_html_a7a1d5eec194db0977b2318c6ed6a2b86"><divclass="ttname"><ahref="structfaiss_1_1IndexIVF.html#a7a1d5eec194db0977b2318c6ed6a2b86">faiss::IndexIVF::train</a></div><divclass="ttdeci">virtual void train(idx_t n, const float *x) override</div><divclass="ttdoc">Trains the quantizer and calls train_residual to train sub-quantizers. </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8cpp_source.html#l00096">IndexIVF.cpp:96</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVFFlat_html_a5f7356766632d3ce2838f285aa6b8e76"><divclass="ttname"><ahref="structfaiss_1_1IndexIVFFlat.html#a5f7356766632d3ce2838f285aa6b8e76">faiss::IndexIVFFlat::add_with_ids</a></div><divclass="ttdeci">virtual void add_with_ids(idx_t n, const float *x, const long *xids) override</div><divclass="ttdoc">implemented for all IndexIVF* classes </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8cpp_source.html#l00224">IndexIVF.cpp:224</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVF_html_aed2e9757ad5f3c234fd8ad60175a2a73"><divclass="ttname"><ahref="structfaiss_1_1IndexIVF.html#aed2e9757ad5f3c234fd8ad60175a2a73">faiss::IndexIVF::own_fields</a></div><divclass="ttdeci">bool own_fields</div><divclass="ttdoc">whether object owns the quantizer </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8h_source.html#l00052">IndexIVF.h:52</a></div></div>
<divclass="ttc"id="structfaiss_1_1Index_html_a040c6aed1f224f3ea7bf58eebc0c31a4"><divclass="ttname"><ahref="structfaiss_1_1Index.html#a040c6aed1f224f3ea7bf58eebc0c31a4">faiss::Index::idx_t</a></div><divclass="ttdeci">long idx_t</div><divclass="ttdoc">all indices are this type </div><divclass="ttdef"><b>Definition:</b><ahref="Index_8h_source.html#l00064">Index.h:64</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVFFlat_html_a9df8b023486f54c8f2c5452787807360"><divclass="ttname"><ahref="structfaiss_1_1IndexIVFFlat.html#a9df8b023486f54c8f2c5452787807360">faiss::IndexIVFFlat::reset</a></div><divclass="ttdeci">virtual void reset() override</div><divclass="ttdoc">removes all elements from the database. </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8cpp_source.html#l00468">IndexIVF.cpp:468</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVF_html_aae6f0fae1f0721af3aa0b5ea1bd9980d"><divclass="ttname"><ahref="structfaiss_1_1IndexIVF.html#aae6f0fae1f0721af3aa0b5ea1bd9980d">faiss::IndexIVF::make_direct_map</a></div><divclass="ttdeci">void make_direct_map()</div><divclass="ttdoc">intialize a direct map </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8cpp_source.html#l00069">IndexIVF.cpp:69</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVF_html_a47a3b7665e9d2be41c6d3b2e9144b73f"><divclass="ttname"><ahref="structfaiss_1_1IndexIVF.html#a47a3b7665e9d2be41c6d3b2e9144b73f">faiss::IndexIVF::reset</a></div><divclass="ttdeci">virtual void reset() override</div><divclass="ttdoc">removes all elements from the database. </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8cpp_source.html#l00087">IndexIVF.cpp:87</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVF_html_a513dfec3a250f08a9fdd18a24178e6bb"><divclass="ttname"><ahref="structfaiss_1_1IndexIVF.html#a513dfec3a250f08a9fdd18a24178e6bb">faiss::IndexIVF::print_stats</a></div><divclass="ttdeci">void print_stats() const </div><divclass="ttdoc">display some stats about the inverted lists </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8cpp_source.html#l00143">IndexIVF.cpp:143</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVF_html_ab38fde4c923abefc4185eb7450b5b95b"><divclass="ttname"><ahref="structfaiss_1_1IndexIVF.html#ab38fde4c923abefc4185eb7450b5b95b">faiss::IndexIVF::nlist</a></div><divclass="ttdeci">size_t nlist</div><divclass="ttdoc">number of possible key values </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8h_source.html#l00047">IndexIVF.h:47</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVF_html_a821002a9d3a1a74dc8d6f6072eca4075"><divclass="ttname"><ahref="structfaiss_1_1IndexIVF.html#a821002a9d3a1a74dc8d6f6072eca4075">faiss::IndexIVF::add</a></div><divclass="ttdeci">virtual void add(idx_t n, const float *x) override</div><divclass="ttdoc">Quantizes x and calls add_with_key. </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8cpp_source.html#l00064">IndexIVF.cpp:64</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVFFlat_html_a5ac4f051396a1535426baec8f401aa93"><divclass="ttname"><ahref="structfaiss_1_1IndexIVFFlat.html#a5ac4f051396a1535426baec8f401aa93">faiss::IndexIVFFlat::search_knn_inner_product</a></div><divclass="ttdeci">void search_knn_inner_product(size_t nx, const float *x, const long *keys, float_minheap_array_t *res) const </div><divclass="ttdoc">Implementation of the search for the inner product metric. </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8cpp_source.html#l00273">IndexIVF.cpp:273</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVF_html_aedd0c14b5654295b291638ec7f9f9517"><divclass="ttname"><ahref="structfaiss_1_1IndexIVF.html#aedd0c14b5654295b291638ec7f9f9517">faiss::IndexIVF::maintain_direct_map</a></div><divclass="ttdeci">bool maintain_direct_map</div><divclass="ttdoc">map for direct access to the elements. Enables reconstruct(). </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8h_source.html#l00059">IndexIVF.h:59</a></div></div>
<divclass="ttc"id="namespacefaiss_html_afd12191c638da74760ff397cf319752c"><divclass="ttname"><ahref="namespacefaiss.html#afd12191c638da74760ff397cf319752c">faiss::MetricType</a></div><divclass="ttdeci">MetricType</div><divclass="ttdoc">Some algorithms support both an inner product vetsion and a L2 search version. </div><divclass="ttdef"><b>Definition:</b><ahref="Index_8h_source.html#l00044">Index.h:44</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVFFlat_html_aea729c3d8c70bdd93f8e413e834851a4"><divclass="ttname"><ahref="structfaiss_1_1IndexIVFFlat.html#aea729c3d8c70bdd93f8e413e834851a4">faiss::IndexIVFFlat::add_core</a></div><divclass="ttdeci">void add_core(idx_t n, const float *x, const long *xids, const long *precomputed_idx)</div><divclass="ttdoc">same as add_with_ids, with precomputed coarse quantizer </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8cpp_source.html#l00229">IndexIVF.cpp:229</a></div></div>
