Added automatic stopping for MonteCarloReward

pull/87/head
AlessandroBregoli 2 years ago
parent 5d676be180
commit adb0f99419
  1. 4
      reCTBN/src/parameter_learning.rs
  2. 2
      reCTBN/src/reward.rs
  3. 89
      reCTBN/src/reward/reward_evaluation.rs
  4. 6
      reCTBN/tests/reward_evaluation.rs

@ -144,9 +144,7 @@ impl ParameterLearning for BayesianApproach {
.zip(M.mapv(|x| x as f64).axis_iter(Axis(2)))
.for_each(|(mut C, m)| C.assign(&(&m.mapv(|y| y + alpha) / &T.mapv(|y| y + tau))));
CIM.outer_iter_mut()
.for_each(|mut C| {
CIM.outer_iter_mut().for_each(|mut C| {
C.diag_mut().fill(0.0);
});

@ -1,5 +1,5 @@
pub mod reward_function;
pub mod reward_evaluation;
pub mod reward_function;
use std::collections::HashMap;

@ -1,11 +1,11 @@
use std::collections::HashMap;
use rayon::prelude::{IntoParallelIterator, ParallelIterator};
use statrs::distribution::ContinuousCDF;
use crate::params::{self, ParamsTrait};
use crate::process;
use crate::{
process::NetworkProcessState,
reward::RewardEvaluation,
@ -14,11 +14,13 @@ use crate::{
pub enum RewardCriteria {
FiniteHorizon,
InfiniteHorizon {discount_factor: f64},
InfiniteHorizon { discount_factor: f64 },
}
pub struct MonteCarloReward {
n_iterations: usize,
max_iterations: usize,
max_err_stop: f64,
alpha_stop: f64,
end_time: f64,
reward_criteria: RewardCriteria,
seed: Option<u64>,
@ -26,13 +28,17 @@ pub struct MonteCarloReward {
impl MonteCarloReward {
pub fn new(
n_iterations: usize,
max_iterations: usize,
max_err_stop: f64,
alpha_stop: f64,
end_time: f64,
reward_criteria: RewardCriteria,
seed: Option<u64>,
) -> MonteCarloReward {
MonteCarloReward {
n_iterations,
max_iterations,
max_err_stop,
alpha_stop,
end_time,
reward_criteria,
seed,
@ -58,7 +64,8 @@ impl RewardEvaluation for MonteCarloReward {
let n_states: usize = variables_domain.iter().map(|x| x.len()).product();
(0..n_states).into_par_iter()
(0..n_states)
.into_par_iter()
.map(|s| {
let state: process::NetworkProcessState = variables_domain
.iter()
@ -85,10 +92,13 @@ impl RewardEvaluation for MonteCarloReward {
) -> f64 {
let mut sampler =
ForwardSampler::new(network_process, self.seed.clone(), Some(state.clone()));
let mut ret = 0.0;
let mut expected_value = 0.0;
let mut squared_expected_value = 0.0;
let normal = statrs::distribution::Normal::new(0.0, 1.0).unwrap();
for _i in 0..self.n_iterations {
for i in 0..self.max_iterations {
sampler.reset();
let mut ret = 0.0;
let mut previous = sampler.next().unwrap();
while previous.t < self.end_time {
let current = sampler.next().unwrap();
@ -96,7 +106,7 @@ impl RewardEvaluation for MonteCarloReward {
let r = reward_function.call(&previous.state, None);
let discount = match self.reward_criteria {
RewardCriteria::FiniteHorizon => self.end_time - previous.t,
RewardCriteria::InfiniteHorizon {discount_factor} => {
RewardCriteria::InfiniteHorizon { discount_factor } => {
std::f64::consts::E.powf(-discount_factor * previous.t)
- std::f64::consts::E.powf(-discount_factor * self.end_time)
}
@ -105,8 +115,8 @@ impl RewardEvaluation for MonteCarloReward {
} else {
let r = reward_function.call(&previous.state, Some(&current.state));
let discount = match self.reward_criteria {
RewardCriteria::FiniteHorizon => current.t-previous.t,
RewardCriteria::InfiniteHorizon {discount_factor} => {
RewardCriteria::FiniteHorizon => current.t - previous.t,
RewardCriteria::InfiniteHorizon { discount_factor } => {
std::f64::consts::E.powf(-discount_factor * previous.t)
- std::f64::consts::E.powf(-discount_factor * current.t)
}
@ -114,51 +124,74 @@ impl RewardEvaluation for MonteCarloReward {
ret += discount * r.instantaneous_reward;
ret += match self.reward_criteria {
RewardCriteria::FiniteHorizon => 1.0,
RewardCriteria::InfiniteHorizon {discount_factor} => {
RewardCriteria::InfiniteHorizon { discount_factor } => {
std::f64::consts::E.powf(-discount_factor * current.t)
}
} * r.transition_reward;
}
previous = current;
}
let float_i = i as f64;
expected_value =
expected_value * float_i as f64 / (float_i + 1.0) + ret / (float_i + 1.0);
squared_expected_value = squared_expected_value * float_i as f64 / (float_i + 1.0)
+ ret.powi(2) / (float_i + 1.0);
if i > 2 {
let var =
(float_i + 1.0) / float_i * (squared_expected_value - expected_value.powi(2));
if self.alpha_stop
- 2.0 * normal.cdf(-(float_i + 1.0).sqrt() * self.max_err_stop / var.sqrt())
> 0.0
{
return expected_value;
}
}
}
ret / self.n_iterations as f64
expected_value
}
}
pub struct NeighborhoodRelativeReward<RE: RewardEvaluation> {
inner_reward: RE
inner_reward: RE,
}
impl<RE: RewardEvaluation> NeighborhoodRelativeReward<RE>{
pub fn new(inner_reward: RE) -> NeighborhoodRelativeReward<RE>{
NeighborhoodRelativeReward {inner_reward}
impl<RE: RewardEvaluation> NeighborhoodRelativeReward<RE> {
pub fn new(inner_reward: RE) -> NeighborhoodRelativeReward<RE> {
NeighborhoodRelativeReward { inner_reward }
}
}
impl<RE:RewardEvaluation> RewardEvaluation for NeighborhoodRelativeReward<RE> {
impl<RE: RewardEvaluation> RewardEvaluation for NeighborhoodRelativeReward<RE> {
fn evaluate_state_space<N: process::NetworkProcess, R: super::RewardFunction>(
&self,
network_process: &N,
reward_function: &R,
) -> HashMap<process::NetworkProcessState, f64> {
let absolute_reward = self.inner_reward.evaluate_state_space(network_process, reward_function);
let absolute_reward = self
.inner_reward
.evaluate_state_space(network_process, reward_function);
//This approach optimize memory. Maybe optimizing execution time can be better.
absolute_reward.iter().map(|(k1, v1)| {
let mut max_val:f64 = 1.0;
absolute_reward.iter().for_each(|(k2,v2)| {
let count_diff:usize = k1.iter().zip(k2.iter()).map(|(s1, s2)| if s1 == s2 {0} else {1}).sum();
absolute_reward
.iter()
.map(|(k1, v1)| {
let mut max_val: f64 = 1.0;
absolute_reward.iter().for_each(|(k2, v2)| {
let count_diff: usize = k1
.iter()
.zip(k2.iter())
.map(|(s1, s2)| if s1 == s2 { 0 } else { 1 })
.sum();
if count_diff < 2 {
max_val = max_val.max(v1/v2);
max_val = max_val.max(v1 / v2);
}
});
(k1.clone(), max_val)
}).collect()
})
.collect()
}
fn evaluate_state<N: process::NetworkProcess, R: super::RewardFunction>(

@ -33,7 +33,7 @@ fn simple_factored_reward_function_binary_node_MC() {
let s0: NetworkProcessState = vec![params::StateType::Discrete(0)];
let s1: NetworkProcessState = vec![params::StateType::Discrete(1)];
let mc = MonteCarloReward::new(100, 10.0, RewardCriteria::InfiniteHorizon { discount_factor: 1.0 }, Some(215));
let mc = MonteCarloReward::new(10000, 1e-1, 1e-1, 10.0, RewardCriteria::InfiniteHorizon { discount_factor: 1.0 }, Some(215));
assert_abs_diff_eq!(3.0, mc.evaluate_state(&net, &rf, &s0), epsilon = 1e-2);
assert_abs_diff_eq!(3.0, mc.evaluate_state(&net, &rf, &s1), epsilon = 1e-2);
@ -42,7 +42,7 @@ fn simple_factored_reward_function_binary_node_MC() {
assert_abs_diff_eq!(3.0, rst[&s1], epsilon = 1e-2);
let mc = MonteCarloReward::new(100, 10.0, RewardCriteria::FiniteHorizon, Some(215));
let mc = MonteCarloReward::new(10000, 1e-1, 1e-1, 10.0, RewardCriteria::FiniteHorizon, Some(215));
assert_abs_diff_eq!(30.0, mc.evaluate_state(&net, &rf, &s0), epsilon = 1e-2);
assert_abs_diff_eq!(30.0, mc.evaluate_state(&net, &rf, &s1), epsilon = 1e-2);
@ -113,7 +113,7 @@ fn simple_factored_reward_function_chain_MC() {
params::StateType::Discrete(0),
];
let mc = MonteCarloReward::new(1000, 10.0, RewardCriteria::InfiniteHorizon { discount_factor: 1.0 }, Some(215));
let mc = MonteCarloReward::new(10000, 1e-1, 1e-1, 10.0, RewardCriteria::InfiniteHorizon { discount_factor: 1.0 }, Some(215));
assert_abs_diff_eq!(2.447, mc.evaluate_state(&net, &rf, &s000), epsilon = 1e-1);
let rst = mc.evaluate_state_space(&net, &rf);

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