diff options
Diffstat (limited to 'utils/mfcr.h')
| -rw-r--r-- | utils/mfcr.h | 68 |
1 files changed, 36 insertions, 32 deletions
diff --git a/utils/mfcr.h b/utils/mfcr.h index aeaf599d..6cc0ebf1 100644 --- a/utils/mfcr.h +++ b/utils/mfcr.h @@ -8,6 +8,7 @@ #include <list> #include <iostream> #include <vector> +#include <iterator> #include <tr1/unordered_map> #include <boost/functional/hash.hpp> #include "sampler.h" @@ -35,12 +36,11 @@ std::ostream& operator<<(std::ostream& o, const TableCount& tc) { // referenced therein. // http://www.aclweb.org/anthology/P/P09/P09-2085.pdf // -template <typename Dish, typename DishHash = boost::hash<Dish> > +template <unsigned Floors, typename Dish, typename DishHash = boost::hash<Dish> > class MFCR { public: - MFCR(unsigned num_floors, double d, double strength) : - num_floors_(num_floors), + MFCR(double d, double strength) : num_tables_(), num_customers_(), discount_(d), @@ -50,8 +50,7 @@ class MFCR { strength_prior_shape_(std::numeric_limits<double>::quiet_NaN()), strength_prior_rate_(std::numeric_limits<double>::quiet_NaN()) {} - MFCR(unsigned num_floors, double discount_strength, double discount_beta, double strength_shape, double strength_rate, double d = 0.9, double strength = 10.0) : - num_floors_(num_floors), + MFCR(double discount_strength, double discount_beta, double strength_shape, double strength_rate, double d = 0.9, double strength = 10.0) : num_tables_(), num_customers_(), discount_(d), @@ -111,22 +110,22 @@ class MFCR { } // returns (delta, floor) indicating whether a new table (delta) was opened and on which floor - TableCount increment(const Dish& dish, const std::vector<double>& p0s, const std::vector<double>& lambdas, MT19937* rng) { - assert(p0s.size() == num_floors_); - assert(lambdas.size() == num_floors_); - + template <class InputIterator, class InputIterator2> + TableCount increment(const Dish& dish, InputIterator p0s, InputIterator2 lambdas, MT19937* rng) { DishLocations& loc = dish_locs_[dish]; // marg_p0 = marginal probability of opening a new table on any floor with label dish - const double marg_p0 = std::inner_product(p0s.begin(), p0s.end(), lambdas.begin(), 0.0); - assert(marg_p0 <= 1.0); + typedef typename std::iterator_traits<InputIterator>::value_type F; + const F marg_p0 = std::inner_product(p0s, p0s + Floors, lambdas, F(0.0)); + assert(marg_p0 <= F(1.0001)); int floor = -1; bool share_table = false; if (loc.total_dish_count_) { - const double p_empty = (strength_ + num_tables_ * discount_) * marg_p0; - const double p_share = (loc.total_dish_count_ - loc.table_counts_.size() * discount_); + const F p_empty = F(strength_ + num_tables_ * discount_) * marg_p0; + const F p_share = F(loc.total_dish_count_ - loc.table_counts_.size() * discount_); share_table = rng->SelectSample(p_empty, p_share); } if (share_table) { + // this can be done with doubles since P0 (which may be tiny) is not involved double r = rng->next() * (loc.total_dish_count_ - loc.table_counts_.size() * discount_); for (typename std::list<TableCount>::iterator ti = loc.table_counts_.begin(); ti != loc.table_counts_.end(); ++ti) { @@ -143,12 +142,18 @@ class MFCR { assert(r <= 0.0); } } else { // sit at currently empty table -- must sample what floor - double r = rng->next() * marg_p0; - for (unsigned i = 0; i < p0s.size(); ++i) { - r -= p0s[i] * lambdas[i]; - if (r <= 0.0) { - floor = i; - break; + if (Floors == 1) { + floor = 0; + } else { + F r = F(rng->next()) * marg_p0; + for (unsigned i = 0; i < Floors; ++i) { + r -= (*p0s) * (*lambdas); + ++p0s; + ++lambdas; + if (r <= F(0.0)) { + floor = i; + break; + } } } assert(floor >= 0); @@ -200,18 +205,18 @@ class MFCR { return TableCount(delta, floor); } - double prob(const Dish& dish, const std::vector<double>& p0s, const std::vector<double>& lambdas) const { - assert(p0s.size() == num_floors_); - assert(lambdas.size() == num_floors_); - const double marg_p0 = std::inner_product(p0s.begin(), p0s.end(), lambdas.begin(), 0.0); - assert(marg_p0 <= 1.0); + template <class InputIterator, class InputIterator2> + typename std::iterator_traits<InputIterator>::value_type prob(const Dish& dish, InputIterator p0s, InputIterator2 lambdas) const { + typedef typename std::iterator_traits<InputIterator>::value_type F; + const F marg_p0 = std::inner_product(p0s, p0s + Floors, lambdas, F(0.0)); + assert(marg_p0 <= F(1.0001)); const typename std::tr1::unordered_map<Dish, DishLocations, DishHash>::const_iterator it = dish_locs_.find(dish); - const double r = num_tables_ * discount_ + strength_; + const F r = F(num_tables_ * discount_ + strength_); if (it == dish_locs_.end()) { - return r * marg_p0 / (num_customers_ + strength_); + return r * marg_p0 / F(num_customers_ + strength_); } else { - return (it->second.total_dish_count_ - discount_ * it->second.table_counts_.size() + r * marg_p0) / - (num_customers_ + strength_); + return (F(it->second.total_dish_count_ - discount_ * it->second.table_counts_.size()) + F(r * marg_p0)) / + F(num_customers_ + strength_); } } @@ -303,7 +308,7 @@ class MFCR { }; void Print(std::ostream* out) const { - (*out) << "MFCR(d=" << discount_ << ",strength=" << strength_ << ") customers=" << num_customers_ << std::endl; + (*out) << "MFCR<" << Floors << ">(d=" << discount_ << ",strength=" << strength_ << ") customers=" << num_customers_ << std::endl; for (typename std::tr1::unordered_map<Dish, DishLocations, DishHash>::const_iterator it = dish_locs_.begin(); it != dish_locs_.end(); ++it) { (*out) << it->first << " (" << it->second.total_dish_count_ << " on " << it->second.table_counts_.size() << " tables): "; @@ -323,7 +328,6 @@ class MFCR { return dish_locs_.end(); } - unsigned num_floors_; unsigned num_tables_; unsigned num_customers_; std::tr1::unordered_map<Dish, DishLocations, DishHash> dish_locs_; @@ -340,8 +344,8 @@ class MFCR { double strength_prior_rate_; }; -template <typename T,typename H> -std::ostream& operator<<(std::ostream& o, const MFCR<T,H>& c) { +template <unsigned N,typename T,typename H> +std::ostream& operator<<(std::ostream& o, const MFCR<N,T,H>& c) { c.Print(&o); return o; } |