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/*
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
#include <cstdio>
#include <cstdlib>
#include <random>
#include <faiss/IndexFlat.h>
#include <faiss/IndexIVFPQ.h>
using idx_t = faiss::idx_t;
int main() {
int d = 64; // dimension
int nb = 100000; // database size
int nq = 10000; // nb of queries
std::mt19937 rng;
std::uniform_real_distribution<> distrib;
float* xb = new float[d * nb];
float* xq = new float[d * nq];
for (int i = 0; i < nb; i++) {
for (int j = 0; j < d; j++) {
xb[d * i + j] = distrib(rng);
}
xb[d * i] += i / 1000.;
}
for (int i = 0; i < nq; i++) {
for (int j = 0; j < d; j++) {
xq[d * i + j] = distrib(rng);
}
xq[d * i] += i / 1000.;
}
int nlist = 100;
int k = 4;
int m = 8; // bytes per vector
faiss::IndexFlatL2 quantizer(d); // the other index
faiss::IndexIVFPQ index(&quantizer, d, nlist, m, 8);
index.train(nb, xb);
index.add(nb, xb);
{ // sanity check
idx_t* I = new idx_t[k * 5];
float* D = new float[k * 5];
index.search(5, xb, k, D, I);
printf("I=\n");
for (int i = 0; i < 5; i++) {
for (int j = 0; j < k; j++) {
printf("%5zd ", I[i * k + j]);
}
printf("\n");
}
printf("D=\n");
for (int i = 0; i < 5; i++) {
for (int j = 0; j < k; j++) {
printf("%7g ", D[i * k + j]);
}
printf("\n");
}
delete[] I;
delete[] D;
}
{ // search xq
idx_t* I = new idx_t[k * nq];
float* D = new float[k * nq];
index.nprobe = 10;
index.search(nq, xq, k, D, I);
printf("I=\n");
for (int i = nq - 5; i < nq; i++) {
for (int j = 0; j < k; j++) {
printf("%5zd ", I[i * k + j]);
}
printf("\n");
}
delete[] I;
delete[] D;
}
delete[] xb;
delete[] xq;
return 0;
}
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