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| author | Bertrand <bertrand.horel@gmail.com> | 2016-02-08 14:40:20 +0000 |
|---|---|---|
| committer | Bertrand <bertrand.horel@gmail.com> | 2016-02-08 14:40:20 +0000 |
| commit | a86b1d918a4c31f74024aa6b42fa0021919585de (patch) | |
| tree | d8fdea76dabb3fdd04714c413030c290215dc8e5 /stratified_sampling.hpp | |
| parent | f339746cc182a746087e3637c9425b1b5f0b0ab2 (diff) | |
| download | projet_C++-a86b1d918a4c31f74024aa6b42fa0021919585de.tar.gz | |
débuggage et seeding
Diffstat (limited to 'stratified_sampling.hpp')
| -rw-r--r-- | stratified_sampling.hpp | 126 |
1 files changed, 101 insertions, 25 deletions
diff --git a/stratified_sampling.hpp b/stratified_sampling.hpp index b63cd52..0b0b4ef 100644 --- a/stratified_sampling.hpp +++ b/stratified_sampling.hpp @@ -1,4 +1,6 @@ #include <vector> +#include <algorithm> +#include <iostream> #include <gsl/gsl_rng.h> #include "rtnorm.hpp" @@ -9,43 +11,117 @@ struct var_alea { typedef T result_type; var_alea() : value(0) {}; var_alea(T value) : value(value) {}; - virtual ~var_alea() {}; + virtual ~var_alea() {}; virtual T operator()() = 0; T current() const { return value; }; - protected: - T value; +protected: + T value; }; typedef var_alea<double> var_alea_real; struct gaussian_truncated : public var_alea_real { - gaussian_truncated(double a, double b, double mean=0, double sigma=1) - :a(a), b(b), mean(mean), sigma(sigma) { - const gsl_rng_type* type = gsl_rng_default; - gen = gsl_rng_alloc(type); - }; - double operator()() { - pair<double, double> p = rtnorm(gen, a, b, mean, sigma); - return value = p.first; - }; - ~gaussian_truncated() { gsl_rng_free(gen); } + gaussian_truncated(double a, double b, double mean=0, double sigma=1, int seed=0) + :a(a), b(b), mean(mean), sigma(sigma), seed(seed) { + const gsl_rng_type* type = gsl_rng_default; + gen = gsl_rng_alloc(type); + gsl_rng_set(gen, seed); + }; + gaussian_truncated(gaussian_truncated const &other) + :a(other.a),b(other.b), mean(other.mean),sigma(other.sigma){ + gen = gsl_rng_clone(other.gen); + }; + + double operator()() { + pair<double, double> p = rtnorm(gen, a, b, mean, sigma); + return value = p.first; + }; + + ~gaussian_truncated() { gsl_rng_free(gen); } private: - double mean, sigma, a, b; - gsl_rng *gen; + int seed; + double mean, sigma, a, b; + gsl_rng *gen; }; template <typename Gen> struct stratified_sampling { - stratified_sampling(vector<double> p, vector<Gen> gen) - :p(p), gen(gen) {}; - void update(int N); - //vector<double> get_mean(); - //double estimator(); + stratified_sampling(vector<double> p, vector<Gen> gen) + :p(p), gen(gen), mean(p.size(), 0), sigma(p.size(), 0){}; + void update(int N); + void draw(); + vector<double> get_mean(); + //double estimator(); private: - vector<double> p; - vector<int> M; - vector<double> sigma; - vector<Gen> gen; - + vector<double> p; + vector<int> M; + vector<int> cumM; + vector<double> mean; + vector<double> sigma; + vector<Gen> gen; + +}; + +//actualisation du nombre de tirages à faire par strates +template <typename Gen> +void stratified_sampling<Gen>::update(int Nk) { + int I = p.size(); + bool first_step = M.empty(); + //reinitialistation du vecteur M du nombre de tirages par strates + if (first_step) { + M.resize(I,1); + cumM.resize(I,0); + } + else { + for(int i=0; i<I; i++){ + cumM[i]=cumM[i]+M[i]; + M[i]=1; + } + } + + std::vector<double> m(I, 0); //le vecteur des m_i idéals + + if (first_step) { + for (int i=0; i<I; i++) { + m[i] = (Nk-I)*p[i]; + } + } + else { + double scal = std::inner_product(p.begin(), p.end(), sigma.begin(), (double) 0); + for (int i=0; i < I; i++) { + m[i] = (Nk-I)*p[i]*sigma[i]/scal; + std::cout<<m[i]<<std::endl; + } + } + M[0]+=floor(m[0]); + double current = m[0]; + for (int i=1; i<I; i++){ + M[i] += floor(current+m[i]) - floor(current); + current += m[i]; + cout<<M[i]<<"\t"; + } + cout<<endl; +} + +template <typename Gen> +void stratified_sampling<Gen>::draw() { + int I = p.size(); + double m, s, oldmean; + for(int i=0;i<I;i++){ + m=0; + s=0; + for(int j=0;j<M[i];j++){ + m=m+gen[i](); + s=s+gen[i].current()*gen[i].current(); + } + oldmean=mean[i]; + mean[i]=(mean[i]*cumM[i]+m)/(cumM[i]+M[i]); + sigma[i]=((sigma[i]+oldmean*oldmean)*cumM[i] + s)/(cumM[i]+M[i]) - mean[i]*mean[i]; + } +}; + +template <typename Gen> +vector<double> stratified_sampling<Gen>::get_mean() { + return mean; }; |
