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use{
crate::{*, traits::*},
rand::{Rng, seq::*},
std::{
marker::PhantomData,
io::Write,
iter::*,
collections::*,
convert::*,
num::*
}
};
#[cfg(feature = "serde_support")]
use serde::{Serialize, Deserialize};
#[derive(Debug, Clone)]
#[cfg_attr(feature = "serde_support", derive(Serialize, Deserialize))]
/// Error states, that entropic sampling, or the creation of `EntropicSamplingAdaptive`
/// could encounter
pub enum EntropicErrors {
/// # source (`WangLandauAdaptive`) was in an invalid state
/// * did you forget to use one of the `init*` methods to initialize a valid
/// WangLandau state?
InvalidWangLandau,
/// Still in the process of gathering statistics
/// Not enough to make an estimate
NotEnoughStatistics,
/// Still Gathering Statistics, this is only an estimate!
EstimatedStatistic(Vec<f64>),
/// Invalid trial step. Is your max_step smaller than your min_step?
InvalidMinMaxTrialSteps,
/// # Posible reasons
/// * `log_density.len()` and `histogram.bin_count()` are not equal
/// * not all values of `log_density` are finite
InvalidLogDensity,
/// You are trying to have a `min_best_of_count` that is
/// larger than the total steps you try!
InvalidBestof,
}
/// # Entropic sampling made easy
/// > J. Lee,
/// > “New Monte Carlo algorithm: Entropic sampling,”
/// > Phys. Rev. Lett. 71, 211–214 (1993),
/// > DOI: [10.1103/PhysRevLett.71.211](https://doi.org/10.1103/PhysRevLett.71.211)
#[derive(Debug, Clone)]
#[cfg_attr(feature = "serde_support", derive(Serialize, Deserialize))]
pub struct EntropicSamplingAdaptive<Hist, R, E, S, Res, T>
{
rng: R,
trial_list: Vec<usize>,
best_of_steps: Vec<usize>,
min_best_of_count: usize,
best_of_threshold: f64,
ensemble: E,
steps: Vec<S>,
step_res_marker: PhantomData<Res>,
accepted_step_hist: Vec<usize>,
rejected_step_hist: Vec<usize>,
total_steps_rejected: usize,
total_steps_accepted: usize,
wl_steps_accepted: usize,
wl_steps_rejected: usize,
min_step: usize,
counter: usize,
step_count: usize,
step_goal: usize,
histogram: Hist,
log_density: Vec<f64>,
old_energy: T,
old_bin: usize,
adjust_bestof_every: usize,
}
impl<Hist, R, E, S, Res, Energy> GlueAble<Hist> for EntropicSamplingAdaptive<Hist, R, E, S, Res, Energy>
where Hist: Clone + Histogram
{
fn push_glue_entry_ignoring(
&self,
job: &mut GlueJob<Hist>,
ignore_idx: &[usize]
) {
if !ignore_idx.contains(&0)
{
let mut missing_steps = 0;
if self.step_count() >= self.step_goal()
{
missing_steps = (self.step_goal() - self.step_count()) as u64;
}
let rejected = self.total_entr_steps_rejected() as u64;
let accepted = self.total_entr_steps_accepted() as u64;
let stats = IntervalSimStats{
sim_progress: SimProgress::MissingSteps(missing_steps),
interval_sim_type: SimulationType::Entropic,
rejected_steps: rejected,
accepted_steps: accepted,
replica_exchanges: None,
proposed_replica_exchanges: None,
merged_over_walkers: NonZeroUsize::new(1).unwrap()
};
let glue_entry = GlueEntry{
hist: self.hist().clone(),
prob: self.log_density_refined(),
log_base: LogBase::BaseE,
interval_stats: stats
};
job.collection.push(glue_entry);
}
}
}
impl<Hist, R, E, S, Res, T> TryFrom<WangLandauAdaptive<Hist, R, E, S, Res, T>>
for EntropicSamplingAdaptive<Hist, R, E, S, Res, T>
where
Hist: Histogram,
R: Rng
{
type Error = EntropicErrors;
fn try_from(mut wl: WangLandauAdaptive<Hist, R, E, S, Res, T>) -> Result<Self, Self::Error> {
if wl.old_bin.is_none() || wl.old_energy.is_none() {
return Err(EntropicErrors::InvalidWangLandau);
}
let wl_steps_rejected = wl.total_steps_rejected();
let wl_steps_accepted = wl.total_steps_accepted();
wl.accepted_step_hist
.iter_mut()
.for_each(|v| *v = 0);
wl.rejected_step_hist
.iter_mut()
.for_each(|v| *v = 0);
wl.best_of_steps.clear();
wl.histogram.reset();
wl.trial_list.shuffle(&mut wl.rng);
Ok(
Self{
wl_steps_rejected,
wl_steps_accepted,
counter: 0,
steps: wl.steps,
step_res_marker: wl.step_res_marker,
log_density: wl.log_density,
old_energy: wl.old_energy.unwrap(),
old_bin: wl.old_bin.unwrap(),
accepted_step_hist: wl.accepted_step_hist,
rejected_step_hist: wl.rejected_step_hist,
total_steps_accepted: 0,
total_steps_rejected: 0,
min_step: wl.min_step,
min_best_of_count: wl.min_best_of_count,
best_of_steps: wl.best_of_steps,
best_of_threshold: wl.best_of_threshold,
rng: wl.rng,
trial_list: wl.trial_list,
ensemble: wl.ensemble,
step_count: 0,
step_goal: wl.step_count,
histogram: wl.histogram,
adjust_bestof_every: 10usize.max(4 * wl.check_refine_every),
}
)
}
}
impl<Hist, R, E, S, Res, T> EntropicSamplingAdaptive<Hist, R, E, S, Res, T>
{
/// # Current state of the Ensemble
#[inline]
pub fn ensemble(&self) -> &E
{
&self.ensemble
}
/// # Energy of ensemble
/// * assuming `energy_fn` (see `self.entropic_step` etc.)
/// is deterministic and will allways give the same result for the same ensemble,
/// this returns the energy of the current ensemble
#[inline]
pub fn energy(&self) -> &T
{
&self.old_energy
}
/// # Number of entropic steps done until now
/// * will be reset by [`self.refine_estimate`](#method.refine_estimate)
#[inline]
pub fn step_count(&self) -> usize
{
self.step_count
}
/// # Number of entropic steps to be performed
/// * if `self` was created from `WangLandauAdaptive`,
/// `step_goal` will be equal to the number of WangLandau steps, that were performed
#[inline]
pub fn step_goal(&self) -> usize
{
self.step_goal
}
/// # Number of entropic steps to be performed
/// * set the number of steps to be performed by entropic sampling
#[inline]
pub fn set_step_goal(&mut self, step_goal: usize){
self.step_goal = step_goal;
}
/// # Smallest possible markov step (`m_steps` of MarkovChain trait) by entropic step
#[inline]
pub fn min_step_size(&self) -> usize
{
self.min_step
}
/// # Largest possible markov step (`m_steps` of MarkovChain trait) by entropic step
#[inline]
pub fn max_step_size(&self) -> usize
{
self.min_step + self.accepted_step_hist.len() - 1
}
/// # Currently used best of
/// * might have length 0, if statistics are still being gathered
/// * otherwise this contains the step sizes, from which the next stepsize
/// is drawn uniformly
#[inline]
pub fn best_of_steps(&self) -> &Vec<usize>
{
&self.best_of_steps
}
/// # Fraction of steps accepted since the statistics were reset the last time
/// * (steps accepted since last reset) / (steps since last reset)
/// * `NaN` if no steps were performed yet
pub fn fraction_accepted_current(&self) -> f64 {
let accepted: usize = self.accepted_step_hist.iter().sum();
let total = accepted + self.rejected_step_hist.iter().sum::<usize>();
if total == 0 {
f64::NAN
} else {
accepted as f64 / total as f64
}
}
/// # total number of entropic steps, that were accepted
pub fn total_entr_steps_accepted(&self) -> usize
{
self.total_steps_accepted
+ self.accepted_step_hist
.iter()
.sum::<usize>()
}
/// # total number of entropic steps, that were rejected
pub fn total_entr_steps_rejected(&self) -> usize
{
self.total_steps_rejected
+ self.rejected_step_hist
.iter()
.sum::<usize>()
}
/// # Fraction of steps accepted since the creation of `self`
/// * `NaN` if no steps were performed yet
pub fn fraction_accepted_total_entropic(&self) -> f64 {
let total_acc = self.total_entr_steps_accepted();
let total_steps = total_acc + self.total_entr_steps_rejected();
if total_steps == 0 {
f64::NAN
} else {
total_acc as f64 / total_steps as f64
}
}
/// * returns the (non normalized) log_density estimate log(P(E)), with which the simulation was started
/// * if you created this from a WangLandau simulation, this is the result of the WangLandau Simulation
pub fn log_density_estimate(&self) -> &Vec<f64>
{
&self.log_density
}
/// calculates the (non normalized) log_density estimate log(P(E)) according to the [paper](#entropic-sampling-made-easy)
pub fn log_density_refined(&self) -> Vec<f64>
where Hist: Histogram{
let mut log_density = Vec::with_capacity(self.log_density.len());
log_density.extend(
self.log_density
.iter()
.zip(self.histogram.hist().iter())
.map(
|(&log_p, &h)|
{
if h == 0 {
log_p
} else {
log_p + (h as f64).ln()
}
}
)
);
log_density
}
/// # Return current state of histogram
pub fn hist(&self) -> &Hist
{
&self.histogram
}
}
impl<Hist, R, E, S, Res, T> EntropicSamplingAdaptive<Hist, R, E, S, Res, T>
where Hist: Histogram,
R: Rng
{
/// # Creates EntropicSamplingAdaptive from a `WangLandauAdaptive` state
/// * `WangLandauAdaptive` state needs to be valid, i.e., you must have called one of the `init*` methods
/// - this ensures, that the members `old_energy` and `old_bin` are not `None`
pub fn from_wl_adaptive(wl: WangLandauAdaptive<Hist, R, E, S, Res, T>) -> Result<Self, EntropicErrors>
{
wl.try_into()
}
/// # Calculates `self.log_density_refined` and uses that as estimate for a the entropic sampling simulation
/// * returns old estimate
/// # prepares `self` for a new entropic simulation
/// * sets new estimate for log(P(E))
/// * resets statistic gathering
/// * resets step_count
pub fn refine_estimate(&mut self) -> Vec<f64>
{
let mut estimate = self.log_density_refined();
std::mem::swap(&mut estimate, &mut self.log_density);
self.counter = 0;
self.step_count = 0;
self.best_of_steps.clear();
self.histogram.reset();
self.trial_list.shuffle(&mut self.rng);
self.total_steps_accepted += self.accepted_step_hist.iter().sum::<usize>();
self.accepted_step_hist
.iter_mut()
.for_each(|entry| *entry = 0);
self.total_steps_rejected += self.rejected_step_hist.iter().sum::<usize>();
self.rejected_step_hist
.iter_mut()
.for_each(|entry| *entry = 0);
estimate
}
/// # How often to adjust `bestof_steps`?
/// * if you try to set a value smaller 10, it will be set to 10
/// * will reevalute the statistics every `adjust_bestof_every` steps,
/// - this will not start new statistics gathering but just trigger a reevaluation of
/// the gathered statistics (should be O(max_stepsize - min_stepsize))
#[inline]
pub fn set_adjust_bestof_every(&mut self, adjust_bestof_every: usize)
{
self.adjust_bestof_every = adjust_bestof_every.max(10);
}
/// Is the simulation in the process of rebuilding the statistics,
/// i.e., is it currently trying many differnt step sizes?
#[inline]
pub fn is_rebuilding_statistics(&self) -> bool
{
self.counter < self.trial_list.len()
}
fn statistic_bin_not_hit(&self) -> bool
{
self.accepted_step_hist
.iter()
.zip(self.rejected_step_hist.iter())
.any(|(a, r )| a + r == 0)
}
/// # Estimate accept/reject statistics
/// * contains list of estimated probabilities for accepting a step of corresponding step size
/// * list\[i\] corresponds to step size `i + self.min_step`
/// * O(trial_step_max - trial_step_min)
pub fn estimate_statistics(&self) -> Result<Vec<f64>, WangLandauErrors>
{
let calc_estimate = || {
let mut estimate = Vec::with_capacity(self.accepted_step_hist.len());
estimate.extend(
self.accepted_step_hist
.iter()
.zip(
self.rejected_step_hist.iter()
).map(|(&a, &r)|
{
a as f64 / (a + r) as f64
}
)
);
estimate
};
if self.is_rebuilding_statistics() {
if self.statistic_bin_not_hit()
{
Err(WangLandauErrors::NotEnoughStatistics)
} else{
Err(WangLandauErrors::EstimatedStatistic(calc_estimate()))
}
} else {
Ok(
calc_estimate()
)
}
}
fn generate_bestof(&mut self)
{
let statistics = self.estimate_statistics().unwrap();
let mut heap = BinaryHeap::with_capacity(statistics.len());
heap.extend(statistics.into_iter()
.enumerate()
.map(|(index, prob)|
{
ProbIndex::new(prob, index)
}
)
);
while let Some(p_i) = heap.pop() {
if p_i.is_best_of(self.best_of_threshold)
|| self.best_of_steps.len() < self.min_best_of_count
{
let step_size = p_i.index + self.min_step;
self.best_of_steps.push(step_size);
} else {
break;
}
}
}
fn adjust_bestof(&mut self){
self.best_of_steps.clear();
self.generate_bestof();
}
fn get_stepsize(&mut self) -> usize {
match self.trial_list.get(self.counter) {
None => {
if self.best_of_steps.is_empty(){
self.generate_bestof();
}
else if self.counter % self.adjust_bestof_every == 0 {
self.adjust_bestof();
}
*self.best_of_steps.choose(&mut self.rng).unwrap()
},
Some(&step_size) => {
step_size
},
}
}
#[inline]
fn count_accepted(&mut self, size: usize){
self.accepted_step_hist[size - self.min_step] += 1;
self.counter += 1;
}
#[inline]
fn count_rejected(&mut self, size: usize){
self.rejected_step_hist[size - self.min_step] += 1;
self.counter += 1;
}
/// **panics** if index is invalid
#[inline(always)]
fn metropolis_acception_prob(&self, new_bin: usize) -> f64
{
(self.log_density[self.old_bin] - self.log_density[new_bin])
.exp()
}
}
impl<Hist, R, E, S, Res, T> EntropicSamplingAdaptive<Hist, R, E, S, Res, T>
where Hist: Histogram + HistogramVal<T>,
R: Rng,
E: MarkovChain<S, Res>,
T: Clone,
{
/// # Entropic sampling
/// * performs `self.entropic_step(energy_fn)` until `condition` is false
/// * **Note**: you have access to the current step_count (`self.step_count()`)
/// # Parameter
/// * `energy_fn` function calculating `Some(energy)` of the system
/// or rather the Parameter of which you wish to obtain the probability distribution.
/// If there are any states, for which the calculation is invalid, `None` should be returned
/// * steps resulting in ensembles for which `energy_fn(&mut ensemble)` is `None`
/// will always be rejected
/// * **Important** `energy_fn`: should be the same as used for Wang Landau, otherwise the results will be wrong!
/// * `print_fn`: see below
/// # Correlations
/// * if you want to measure correlations between "energy" and other measurable quantities,
/// use `print_fn`, which will be called after each step - use this function to write to
/// a file or whatever you desire
/// * Note: You do not have to recalculate the energy, if you need it in `print_fn`:
/// just call `self.energy()`
/// * you have access to your ensemble with `self.ensemble()`
/// * if you do not need it, you can use `|_|{}` as `print_fn`
/// ## Safety
/// * While you do have mutable access to the ensemble, the energy function should not change the
/// ensemble in a way, which affects the next calculation of the energy
/// * This is intended for usecases, where the energy calculation is more efficient with mutable access, e.g., through using a
/// buffer stored in the ensemble
/// * Note: I chose to make this function unsafe to force users to aknowledge the (purely logical) limitations
/// regarding the usage of the mutable ensemble. From a programming point of view this will not lead to
/// any undefined behavior or such regardless of if the user fullfills the requirements
pub unsafe fn entropic_sampling_while_unsafe<F, G, W>(
&mut self,
mut energy_fn: F,
mut print_fn: G,
mut condition: W
) where F: FnMut(&mut E) -> Option<T>,
G: FnMut(&Self),
W: FnMut(&Self) -> bool
{
while condition(self) {
self.entropic_step_unsafe(&mut energy_fn);
print_fn(self);
}
}
/// # Entropic sampling
/// * performs `self.entropic_step(energy_fn)` until `condition` is false
/// * **Note**: you have access to the current step_count (`self.step_count()`)
/// # Parameter
/// * `energy_fn` function calculating `Some(energy)` of the system
/// or rather the Parameter of which you wish to obtain the probability distribution.
/// If there are any states, for which the calculation is invalid, `None` should be returned
/// * steps resulting in ensembles for which `energy_fn(&mut ensemble)` is `None`
/// will always be rejected
/// * **Important** `energy_fn`: should be the same as used for Wang Landau, otherwise the results will be wrong!
/// * `print_fn`: see below
/// # Correlations
/// * if you want to measure correlations between "energy" and other measurable quantities,
/// use `print_fn`, which will be called after each step - use this function to write to
/// a file or whatever you desire
/// * Note: You do not have to recalculate the energy, if you need it in `print_fn`:
/// just call `self.energy()`
/// * you have access to your ensemble with `self.ensemble()`
/// * if you do not need it, you can use `|_|{}` as `print_fn`
pub fn entropic_sampling_while<F, G, W>(
&mut self,
mut energy_fn: F,
mut print_fn: G,
mut condition: W
) where F: FnMut(&E) -> Option<T>,
G: FnMut(&Self),
W: FnMut(&Self) -> bool
{
while condition(self) {
self.entropic_step(&mut energy_fn);
print_fn(self);
}
}
/// # Entropic sampling using an accumulating markov step
/// * performs `self.entropic_step_acc(&mut energy_fn)` until `condition(self) == false`
/// # Parameter
/// * `energy_fn` function calculating the energy `E` of the system
/// (or rather the Parameter of which you wish to obtain the probability distribution)
/// during the markov steps, which can be more efficient.
/// * **Important** `energy_fn`: should be the same as used for Wang Landau, otherwise the results will be wrong!
/// * `print_fn`: see below
/// # Correlations
/// * if you want to measure correlations between "energy" and other measurable quantities,
/// use `print_fn`, which will be called after each step - use this function to write to
/// a file or whatever you desire
/// * Note: You do not have to recalculate the energy, if you need it in `print_fn`:
/// just call `self.energy()`
/// * you have access to your ensemble with `self.ensemble()`
/// * if you do not need it, you can use `|_|{}` as `print_fn`
pub fn entropic_sampling_while_acc<F, G, W>(
&mut self,
mut energy_fn: F,
mut print_fn: G,
mut condition: W
) where F: FnMut(&E, &S, &mut T),
G: FnMut(&Self),
W: FnMut(&Self) -> bool
{
while condition(self) {
self.entropic_step_acc(&mut energy_fn);
print_fn(self);
}
}
/// # Entropic sampling
/// * if possible, use `self.entropic_sampling()` instead!
/// * More powerful version of `self.entropic_sampling()`, since you now have mutable access
/// * to access ensemble mutable, use `self.ensemble_mut()`
/// * Note: Whatever you do with the ensemble (or self), should not change the result of the energy function, if performed again.
/// Otherwise the results will be false!
/// * performs `self.entropic_step_unsafe(energy_fn)` until `self.step_count == self.step_goal`
/// # Parameter
/// * `energy_fn` function calculating `Some(energy)` of the system
/// or rather the Parameter of which you wish to obtain the probability distribution.
/// If there are any states, for which the calculation is invalid, `None` should be returned
/// * steps resulting in ensembles for which `energy_fn(&mut ensemble)` is `None`
/// will always be rejected
/// * **Important** `energy_fn`: should be the same as used for Wang Landau, otherwise the results will be wrong!
/// * `print_fn`: see below
/// # Correlations
/// * if you want to measure correlations between "energy" and other measurable quantities,
/// use `print_fn`, which will be called after each step - use this function to write to
/// a file or whatever you desire
/// * Note: You do not have to recalculate the energy, if you need it in `print_fn`:
/// just call `self.energy()`
/// * you have access to your ensemble with `self.ensemble()`
/// * if you do not need it, you can use `|_|{}` as `print_fn`
/// ## Safety
/// * While you do have mutable access to the ensemble, the energy function should not change the
/// ensemble in a way, which affects the next calculation of the energy
/// * This is intended for usecases, where the energy calculation is more efficient with mutable access, e.g., through using a
/// buffer stored in the ensemble
/// * Note: I chose to make this function unsafe to force users to aknowledge the (purely logical) limitations
/// regarding the usage of the mutable ensemble. From a programming point of view this will not lead to
/// any undefined behavior or such regardless of if the user fullfills the requirements
pub unsafe fn entropic_sampling_unsafe<F, G>(
&mut self,
mut energy_fn: F,
mut print_fn: G,
) where F: FnMut(&mut E) -> Option<T>,
G: FnMut(&mut Self)
{
while self.step_count < self.step_goal {
self.entropic_step_unsafe(&mut energy_fn);
print_fn(self);
}
}
/// # Entropic sampling
/// * performs `self.entropic_step(energy_fn)` until `self.step_count == self.step_goal`
/// # Parameter
/// * `energy_fn` function calculating `Some(energy)` of the system
/// or rather the Parameter of which you wish to obtain the probability distribution.
/// If there are any states, for which the calculation is invalid, `None` should be returned
/// * steps resulting in ensembles for which `energy_fn(&mut ensemble)` is `None`
/// will always be rejected
/// * **Important** `energy_fn`: should be the same as used for Wang Landau, otherwise the results will be wrong!
/// * `print_fn`: see below
/// # Correlations
/// * if you want to measure correlations between "energy" and other measurable quantities,
/// use `print_fn`, which will be called after each step - use this function to write to
/// a file or whatever you desire
/// * Note: You do not have to recalculate the energy, if you need it in `print_fn`:
/// just call `self.energy()`
/// * you have access to your ensemble with `self.ensemble()`
/// * if you do not need it, you can use `|_|{}` as `print_fn`
pub fn entropic_sampling<F, G>(
&mut self,
mut energy_fn: F,
mut print_fn: G,
) where F: FnMut(&E) -> Option<T>,
G: FnMut(&Self)
{
while self.step_count < self.step_goal {
self.entropic_step(&mut energy_fn);
print_fn(self);
}
}
/// # Entropic sampling using an accumulating markov step
/// * performs `self.entropic_step_acc(&mut energy_fn)` until `self.step_count == self.step_goal`
/// # Parameter
/// * `energy_fn` function calculating the energy `E` of the system
/// (or rather the Parameter of which you wish to obtain the probability distribution)
/// during the markov steps, which can be more efficient.
/// * **Important** `energy_fn`: should be the same as used for Wang Landau, otherwise the results will be wrong!
/// * `print_fn`: see below
/// # Correlations
/// * if you want to measure correlations between "energy" and other measurable quantities,
/// use `print_fn`, which will be called after each step - use this function to write to
/// a file or whatever you desire
/// * Note: You do not have to recalculate the energy, if you need it in `print_fn`:
/// just call `self.energy()`
/// * you have access to your ensemble with `self.ensemble()`
/// * if you do not need it, you can use `|_|{}` as `print_fn`
pub fn entropic_sampling_acc<F, G>(
&mut self,
mut energy_fn: F,
mut print_fn: G,
) where F: FnMut(&E, &S, &mut T),
G: FnMut(&Self)
{
while self.step_count < self.step_goal {
self.entropic_step_acc(&mut energy_fn);
print_fn(self);
}
}
/// # Entropic step
/// * performs a single step
/// # Parameter
/// * `energy_fn` function calculating `Some(energy)` of the system
/// or rather the Parameter of which you wish to obtain the probability distribution.
/// If there are any states, for which the calculation is invalid, `None` should be returned
/// * steps resulting in ensembles for which `energy_fn(&mut ensemble)` is `None`
/// will always be rejected
/// # Important
/// * `energy_fn`: should be the same as used for Wang Landau, otherwise the results will be wrong!
/// ## Safety
/// * While you do have mutable access to the ensemble, the energy function should not change the
/// ensemble in a way, which affects the next calculation of the energy
/// * This is intended for usecases, where the energy calculation is more efficient with mutable access, e.g., through using a
/// buffer stored in the ensemble
/// * Note: I chose to make this function unsafe to force users to aknowledge the (purely logical) limitations
/// regarding the usage of the mutable ensemble. From a programming point of view this will not lead to
/// any undefined behavior or such regardless of if the user fullfills the requirements
pub unsafe fn entropic_step_unsafe<F>(
&mut self,
mut energy_fn: F,
)where F: FnMut(&mut E) -> Option<T>
{
self.step_count += 1;
let step_size = self.get_stepsize();
self.ensemble.m_steps(step_size, &mut self.steps);
let current_energy = match energy_fn(&mut self.ensemble)
{
Some(energy) => energy,
None => {
self.ensemble.steps_rejected(&self.steps);
self.count_rejected(step_size);
self.histogram.count_index(self.old_bin).unwrap();
self.ensemble.undo_steps_quiet(&self.steps);
return;
}
};
self.entropic_step_helper(current_energy);
}
/// # Entropic step
/// * performs a single step
/// # Parameter
/// * `energy_fn` function calculating `Some(energy)` of the system
/// or rather the Parameter of which you wish to obtain the probability distribution.
/// If there are any states, for which the calculation is invalid, `None` should be returned
/// * steps resulting in ensembles for which `energy_fn(&mut ensemble)` is `None`
/// will always be rejected
/// # Important
/// * `energy_fn`: should be the same as used for Wang Landau, otherwise the results will be wrong!
pub fn entropic_step<F>(
&mut self,
mut energy_fn: F,
)where F: FnMut(&E) -> Option<T>
{
unsafe{
self.entropic_step_unsafe(|e| energy_fn(e))
}
}
/// # Accumulating entropic step
/// * performs a single step
/// # Parameter
/// * `energy_fn` function calculating the energy `E` of the system
/// (or rather the Parameter of which you wish to obtain the probability distribution)
/// during the markov steps, which can be more efficient.
/// # Important
/// * `energy_fn`: should be the same as used for Wang Landau, otherwise the results will be wrong!
pub fn entropic_step_acc<F>(
&mut self,
energy_fn: F,
)
where F: FnMut(&E, &S, &mut T)
{
self.step_count += 1;
let step_size = self.get_stepsize();
let mut current_energy = self.old_energy.clone();
self.ensemble.m_steps_acc(
step_size,
&mut self.steps,
&mut current_energy,
energy_fn
);
self.entropic_step_helper(current_energy);
}
fn entropic_step_helper(&mut self, current_energy: T)
{
let step_size = self.steps.len();
match self.histogram.get_bin_index(¤t_energy)
{
Ok(current_bin) => {
let accept_prob = self.metropolis_acception_prob(current_bin);
if self.rng.gen::<f64>() > accept_prob {
// reject step
self.ensemble.steps_rejected(&self.steps);
self.count_rejected(step_size);
self.ensemble.undo_steps_quiet(&self.steps);
} else {
// accept step
self.ensemble.steps_accepted(&self.steps);
self.count_accepted(step_size);
self.old_energy = current_energy;
self.old_bin = current_bin;
}
},
_ => {
// invalid step -> reject
self.ensemble.steps_rejected(&self.steps);
self.count_rejected(step_size);
self.ensemble.undo_steps_quiet(&self.steps);
}
};
self.histogram.count_index(self.old_bin).unwrap();
}
}
impl<Hist, R, E, S, Res, T> Entropic for EntropicSamplingAdaptive<Hist, R, E, S, Res, T>
where Hist: Histogram,
R: Rng
{
/// # Number of entropic steps done until now
/// * will be reset by [`self.refine_estimate`](#method.refine_estimate)
#[inline]
fn step_counter(&self) -> usize
{
self.step_count
}
fn total_steps_accepted(&self) -> usize {
self.total_entr_steps_accepted() + self.wl_steps_accepted
}
fn total_steps_rejected(&self) -> usize {
self.total_entr_steps_rejected() + self.wl_steps_rejected
}
/// # Number of entropic steps to be performed
/// * if `self` was created from `WangLandauAdaptive`,
/// `step_goal` will be equal to the number of WangLandau steps, that were performed
#[inline]
fn step_goal(&self) -> usize
{
self.step_goal
}
fn log_density(&self) -> Vec<f64> {
self.log_density_refined()
}
fn write_log<W: Write>(&self, mut w: W) -> Result<(), std::io::Error> {
writeln!(w,
"#Acceptance prob_total: {}\n#Acceptance prob current: {}\n#total_steps: {}",
self.fraction_accepted_total(),
self.fraction_accepted_current(),
self.step_counter(),
)?;
writeln!(w, "#min_step_size {}", self.min_step_size())?;
writeln!(w, "#max_step_size {}", self.max_step_size())?;
write!(w, "#Current acception histogram:")?;
for val in self.accepted_step_hist.iter()
{
write!(w, " {}", val)?;
}
write!(w, "\n#Current rejection histogram:")?;
for val in self.rejected_step_hist.iter()
{
write!(w, " {}", val)?;
}
writeln!(w, "\n#bestof threshold: {}", self.best_of_threshold)?;
writeln!(w, "#min_bestof_count: {}", self.min_best_of_count)?;
write!(w, "\n#Current_Bestof:")?;
for val in self.best_of_steps.iter()
{
write!(w, " {}", val)?;
}
write!(w, "#current_statistics_estimate:")?;
let estimate = self.estimate_statistics();
match estimate {
Ok(estimate) => {
for val in estimate
{
write!(w, " {}", val)?;
}
writeln!(w)
},
_ => {
writeln!(w, " None")
}
}
}
}
impl<Hist, R, E, S, Res, Energy> EntropicEnergy<Energy> for EntropicSamplingAdaptive<Hist, R, E, S, Res, Energy>
where Hist: Histogram,
R: Rng,
{
/// # Energy of ensemble
/// * assuming `energy_fn` (see `self.entropic_step` etc.)
/// is deterministic and will allways give the same result for the same ensemble,
/// this returns the energy of the current ensemble
#[inline]
fn energy(&self) -> &Energy
{
&self.old_energy
}
}
impl<Hist, R, E, S, Res, Energy> EntropicHist<Hist> for EntropicSamplingAdaptive<Hist, R, E, S, Res, Energy>
where Hist: Histogram,
R: Rng,
{
#[inline]
fn hist(&self) -> &Hist
{
&self.histogram
}
}
impl<Hist, R, E, S, Res, Energy> EntropicEnsemble<E> for EntropicSamplingAdaptive<Hist, R, E, S, Res, Energy>
where Hist: Histogram,
R: Rng,
{
fn ensemble(&self) -> &E {
&self.ensemble
}
unsafe fn ensemble_mut(&mut self) -> &mut E {
&mut self.ensemble
}
}
impl<Hist, R, E, S, Res, Energy> HasRng<R> for EntropicSamplingAdaptive<Hist, R, E, S, Res, Energy>
where R: Rng,
{
fn rng(&mut self) -> &mut R {
&mut self.rng
}
fn swap_rng(&mut self, rng: &mut R) {
std::mem::swap(&mut self.rng, rng);
}
}