<divclass="line"><aname="l00005"></a><spanclass="lineno"> 5</span> <spanclass="comment"> * This source code is licensed under the BSD+Patents license found in the</span></div>
<divclass="line"><aname="l00006"></a><spanclass="lineno"> 6</span> <spanclass="comment"> * LICENSE file in the root directory of this source tree.</span></div>
<divclass="line"><aname="l00009"></a><spanclass="lineno"> 9</span> <spanclass="comment">// Copyright 2004-present Facebook. All Rights Reserved.</span></div>
<divclass="line"><aname="l00010"></a><spanclass="lineno"> 10</span> <spanclass="comment">// -*- c++ -*-</span></div>
<divclass="line"><aname="l00030"></a><spanclass="lineno"> 30</span> <spanclass="comment"> * In the inverted file, the quantizer (an Index instance) provides a</span></div>
<divclass="line"><aname="l00031"></a><spanclass="lineno"> 31</span> <spanclass="comment"> * quantization index for each vector to be added. The quantization</span></div>
<divclass="line"><aname="l00032"></a><spanclass="lineno"> 32</span> <spanclass="comment"> * index maps to a list (aka inverted list or posting list), where the</span></div>
<divclass="line"><aname="l00033"></a><spanclass="lineno"> 33</span> <spanclass="comment"> * id of the vector is then stored.</span></div>
<divclass="line"><aname="l00035"></a><spanclass="lineno"> 35</span> <spanclass="comment"> * At search time, the vector to be searched is also quantized, and</span></div>
<divclass="line"><aname="l00036"></a><spanclass="lineno"> 36</span> <spanclass="comment"> * only the list corresponding to the quantization index is</span></div>
<divclass="line"><aname="l00037"></a><spanclass="lineno"> 37</span> <spanclass="comment"> * searched. This speeds up the search by making it</span></div>
<divclass="line"><aname="l00038"></a><spanclass="lineno"> 38</span> <spanclass="comment"> * non-exhaustive. This can be relaxed using multi-probe search: a few</span></div>
<divclass="line"><aname="l00039"></a><spanclass="lineno"> 39</span> <spanclass="comment"> * (nprobe) quantization indices are selected and several inverted</span></div>
<divclass="line"><aname="l00040"></a><spanclass="lineno"> 40</span> <spanclass="comment"> * lists are visited.</span></div>
<divclass="line"><aname="l00042"></a><spanclass="lineno"> 42</span> <spanclass="comment"> * Sub-classes implement a post-filtering of the index that refines</span></div>
<divclass="line"><aname="l00043"></a><spanclass="lineno"> 43</span> <spanclass="comment"> * the distance estimation from the query to databse vectors.</span></div>
<divclass="line"><aname="l00046"></a><spanclass="lineno"><aclass="line"href="structfaiss_1_1IndexIVF.html#ab38fde4c923abefc4185eb7450b5b95b"> 46</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="l00047"></a><spanclass="lineno"><aclass="line"href="structfaiss_1_1IndexIVF.html#affed235eadf27a13d753ee4d33a1dc58"> 47</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="l00049"></a><spanclass="lineno"><aclass="line"href="structfaiss_1_1IndexIVF.html#a4b40cc7a70dff41196a3b8769586667a"> 49</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="l00050"></a><spanclass="lineno"><aclass="line"href="structfaiss_1_1IndexIVF.html#a23ee7f75f8be4472a17778f2b33875de"> 50</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="l00051"></a><spanclass="lineno"><aclass="line"href="structfaiss_1_1IndexIVF.html#aed2e9757ad5f3c234fd8ad60175a2a73"> 51</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="l00057"></a><spanclass="lineno"><aclass="line"href="structfaiss_1_1IndexIVF.html#a46d1aeddb60643c5b3f096147c3e028f"> 57</a></span> <spanclass="keywordtype">size_t</span><aclass="code"href="structfaiss_1_1IndexIVF.html#a46d1aeddb60643c5b3f096147c3e028f">code_size</a>; <spanclass="comment">///< code size per vector in bytes</span></div>
<divclass="line"><aname="l00060"></a><spanclass="lineno"> 60</span> <spanclass="comment"> /// map for direct access to the elements. Enables reconstruct().</span></div>
<divclass="line"><aname="l00064"></a><spanclass="lineno"> 64</span> <spanclass="comment"> /** The Inverted file takes a quantizer (an Index) on input,</span></div>
<divclass="line"><aname="l00065"></a><spanclass="lineno"> 65</span> <spanclass="comment"> * which implements the function mapping a vector to a list</span></div>
<divclass="line"><aname="l00066"></a><spanclass="lineno"> 66</span> <spanclass="comment"> * identifier. The pointer is borrowed: the quantizer should not</span></div>
<divclass="line"><aname="l00067"></a><spanclass="lineno"> 67</span> <spanclass="comment"> * be deleted while the IndexIVF is in use.</span></div>
<divclass="line"><aname="l00074"></a><spanclass="lineno"> 74</span> <spanclass="comment"> /// Trains the quantizer and calls train_residual to train sub-quantizers</span></div>
<divclass="line"><aname="l00075"></a><spanclass="lineno"> 75</span> <spanclass="comment"></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="l00085"></a><spanclass="lineno"> 85</span> <spanclass="comment"> /** search a set of vectors, that are pre-quantized by the IVF</span></div>
<divclass="line"><aname="l00086"></a><spanclass="lineno"> 86</span> <spanclass="comment"> * quantizer. Fill in the corresponding heaps with the query</span></div>
<divclass="line"><aname="l00097"></a><spanclass="lineno"> 97</span> <spanclass="comment"> * @param store_pairs store inv list index + inv list offset</span></div>
<divclass="line"><aname="l00098"></a><spanclass="lineno"> 98</span> <spanclass="comment"> * instead in upper/lower 32 bit of result,</span></div>
<divclass="line"><aname="l00099"></a><spanclass="lineno"> 99</span> <spanclass="comment"> * instead of ids (used for reranking).</span></div>
<divclass="line"><aname="l00107"></a><spanclass="lineno"> 107</span> <spanclass="comment"> /** assign the vectors, then call search_preassign */</span></div>
<divclass="line"><aname="l00108"></a><spanclass="lineno"> 108</span> <spanclass="keyword">virtual</span><spanclass="keywordtype">void</span><aclass="code"href="structfaiss_1_1IndexIVF.html#ae2fd47b7d52603659e269aa8f6abb613">search</a> (<aclass="code"href="structfaiss_1_1Index.html#a040c6aed1f224f3ea7bf58eebc0c31a4">idx_t</a> n, <spanclass="keyword">const</span><spanclass="keywordtype">float</span> *x, <aclass="code"href="structfaiss_1_1Index.html#a040c6aed1f224f3ea7bf58eebc0c31a4">idx_t</a> k,</div>
<divclass="line"><aname="l00116"></a><spanclass="lineno"> 116</span> <spanclass="comment"> /** moves the entries from another dataset to self. On output,</span></div>
<divclass="line"><aname="l00117"></a><spanclass="lineno"> 117</span> <spanclass="comment"> * other is empty. add_id is added to all moved ids (for</span></div>
<divclass="line"><aname="l00118"></a><spanclass="lineno"> 118</span> <spanclass="comment"> * sequential ids, this would be this->ntotal */</span></div>
<divclass="line"><aname="l00121"></a><spanclass="lineno"> 121</span> <spanclass="comment"> /** copy a subset of the entries index to the other index</span></div>
<divclass="line"><aname="l00123"></a><spanclass="lineno"> 123</span> <spanclass="comment"> * if subset_type == 0: copies ids in [a1, a2)</span></div>
<divclass="line"><aname="l00124"></a><spanclass="lineno"> 124</span> <spanclass="comment"> * if subset_type == 1: copies ids if id % a1 == a2</span></div>
<divclass="line"><aname="l00125"></a><spanclass="lineno"> 125</span> <spanclass="comment"> * if subset_type == 2: copies inverted lists such that a1</span></div>
<divclass="line"><aname="l00126"></a><spanclass="lineno"> 126</span> <spanclass="comment"> * elements are left before and a2 elements are after</span></div>
<divclass="line"><aname="l00138"></a><spanclass="lineno"> 138</span> <spanclass="comment"> * @param new_maintain_direct_map if true, create a direct map,</span></div>
<divclass="line"><aname="l00146"></a><spanclass="lineno"> 146</span> <spanclass="comment"> /// display some stats about the inverted lists</span></div>
<divclass="line"><aname="l00154"></a><spanclass="lineno"> 154</span> <spanclass="keywordtype">size_t</span> nq; <spanclass="comment">// nb of queries run</span></div>
<divclass="line"><aname="l00155"></a><spanclass="lineno"> 155</span> <spanclass="keywordtype">size_t</span> nlist; <spanclass="comment">// nb of inverted lists scanned</span></div>
<divclass="line"><aname="l00156"></a><spanclass="lineno"> 156</span> <spanclass="keywordtype">size_t</span> ndis; <spanclass="comment">// nb of distancs computed</span></div>
<divclass="line"><aname="l00157"></a><spanclass="lineno"> 157</span> <spanclass="keywordtype">size_t</span> npartial; <spanclass="comment">// nb of bound computations (IndexIVFFlatIPBounds)</span></div>
<divclass="line"><aname="l00170"></a><spanclass="lineno"> 170</span> <spanclass="comment">/** Inverted file with stored vectors. Here the inverted file</span></div>
<divclass="line"><aname="l00171"></a><spanclass="lineno"> 171</span> <spanclass="comment"> * pre-selects the vectors to be searched, but they are not otherwise</span></div>
<divclass="line"><aname="l00172"></a><spanclass="lineno"> 172</span> <spanclass="comment"> * encoded, the code array just contains the raw float entries.</span></div>
<divclass="line"><aname="l00180"></a><spanclass="lineno"> 180</span> <spanclass="comment"> /// same as add_with_ids, with precomputed coarse quantizer</span></div>
<divclass="line"><aname="l00181"></a><spanclass="lineno"> 181</span> <spanclass="comment"></span><spanclass="keyword">virtual</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="l00203"></a><spanclass="lineno"> 203</span> <spanclass="comment"> * @param nv nb of vectors to update</span></div>
<divclass="line"><aname="l00204"></a><spanclass="lineno"> 204</span> <spanclass="comment"> * @param idx vector indices to update, size nv</span></div>
<divclass="line"><aname="l00205"></a><spanclass="lineno"> 205</span> <spanclass="comment"> * @param v vectors of new values, size nv*d</span></div>
<divclass="ttc"id="structfaiss_1_1IndexIVF_html_a2fc63f9bbfe64e05106366465ece2187"><divclass="ttname"><ahref="structfaiss_1_1IndexIVF.html#a2fc63f9bbfe64e05106366465ece2187">faiss::IndexIVF::copy_subset_to</a></div><divclass="ttdeci">virtual void copy_subset_to(IndexIVF &other, int subset_type, long a1, long a2) const </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8cpp_source.html#l00248">IndexIVF.cpp:248</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#l00047">IndexIVF.h:47</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#l00050">IndexIVF.h:50</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#l00055">IndexIVF.h:55</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#l00049">IndexIVF.h:49</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">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#l00155">IndexIVF.cpp:155</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">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#l00325">IndexIVF.cpp:325</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#l00051">IndexIVF.h:51</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#l00062">Index.h:62</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">void reset() override</div><divclass="ttdoc">removes all elements from the database. </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8cpp_source.html#l00110">IndexIVF.cpp:110</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#l00201">IndexIVF.cpp:201</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#l00046">IndexIVF.h:46</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">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_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#l00061">IndexIVF.h:61</a></div></div>
<divclass="ttc"id="structfaiss_1_1IndexIVF_html_a46d1aeddb60643c5b3f096147c3e028f"><divclass="ttname"><ahref="structfaiss_1_1IndexIVF.html#a46d1aeddb60643c5b3f096147c3e028f">faiss::IndexIVF::code_size</a></div><divclass="ttdeci">size_t code_size</div><divclass="ttdoc">code size per vector in bytes </div><divclass="ttdef"><b>Definition:</b><ahref="IndexIVF_8h_source.html#l00057">IndexIVF.h:57</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#l00043">Index.h:43</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">virtual 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#l00330">IndexIVF.cpp:330</a></div></div>
