Struct Trace

pub struct Trace {
    pub log_score: f64,
    pub choices: Choicemap,
}

The trace struct. This holds information about the execution of a gnerative model.

Fields

log_score: f64

The log joint liklihood of all of the random decisions in the trace.

choices: Choicemap

The Choicemap that holds the list of the actual decisions that were made in the execution of the generative model.

Implementations

impl Trace

pub fn new() -> Trace

Create a new blank trace. It begins with an empty choice map and a log score of 0 (which corresponds to a probability of 1.0 when exponentiated.)

pub fn get_trace_string(&self) -> String

Return a string that discribes the random decisions made by the model in this trace.

Example

#[macro_use]
use r_gen::{sample, r_gen}; 
use r_gen::{simulate, distributions::{Value, Distribution}, trace::{Choicemap, Trace}}; 
use std::rc::Rc;

#[r_gen]
fn my_biased_coin_model(():()){
    let p = sample!(format!("p"), Distribution::Beta(1.0, 1.0));            //Sample p from a uniform. 
    sample!(format!("num_heads"), Distribution::Binomial(100, p.into()));   //Flip 100 coins where P(Heads)=p
}
let (trace, result) = simulate(&mut my_biased_coin_model, ()); 
println!("{}", trace.get_trace_string()); 

pub fn sample_weighted_traces(traces: &Vec<Trace>) -> Option<Trace>

Sample a trace from a vector of traces according to a categorical distribution. The weights for the distribution are the scores of the traces rescaled by a normalizing constant. This function is intended to be used in an importance resampling algorithm.

Trait Implementations

impl Clone for Trace

fn clone(&self) -> Trace

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Trace

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for Trace

fn eq(&self, other: &Trace) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Trace

fn partial_cmp(&self, other: &Trace) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.