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switch to L1 norm in hash_bow

This commit is contained in:
Vladyslav Usenko 2019-12-24 16:40:02 +01:00
parent 0f613ef060
commit 9c9587ea54
1 changed files with 7 additions and 6 deletions
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13
include/basalt/hash_bow/hash_bow.h
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@ -47,15 +47,14 @@ class HashBow {
bow_vector.clear(); bow_vector.clear();
double sum_squared = 0; double l1_sum = 0;
for (const auto& kv : bow_map) { for (const auto& kv : bow_map) {
bow_vector.emplace_back(kv); bow_vector.emplace_back(kv);
sum_squared += kv.second * kv.second; l1_sum += std::abs(kv.second);
} }
double norm = std::sqrt(sum_squared);
for (auto& kv : bow_vector) { for (auto& kv : bow_vector) {
kv.second /= norm; kv.second /= l1_sum;
} }
} }
@ -83,13 +82,15 @@ class HashBow {
// if there is a maximum query time select only the frames that have // if there is a maximum query time select only the frames that have
// timestamp below max_t_ns // timestamp below max_t_ns
if (!max_t_ns || v.first.frame_id < (*max_t_ns)) if (!max_t_ns || v.first.frame_id < (*max_t_ns))
scores[v.first] += kv.second * v.second; scores[v.first] += std::abs(kv.second - v.second) -
std::abs(kv.second) - std::abs(v.second);
} }
} }
results.reserve(scores.size()); results.reserve(scores.size());
for (const auto& kv : scores) results.emplace_back(kv); for (const auto& kv : scores)
results.emplace_back(kv.first, -kv.second / 2.0);
std::sort(results.begin(), results.end(), std::sort(results.begin(), results.end(),
[](const auto& a, const auto& b) { return a.second > b.second; }); [](const auto& a, const auto& b) { return a.second > b.second; });