1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172

//! Conjugate component data structure
use lace_data::SparseContainer;
use lace_stats::rv::data::DataOrSuffStat;
use lace_stats::rv::traits::*;
use once_cell::sync::OnceCell;
use rand::Rng;
use serde::{Deserialize, Serialize};

use crate::feature::Component;
use crate::traits::AccumScore;
use crate::traits::{LaceDatum, LaceLikelihood, LaceStat};

/// Maintains a component model and a sufficient statistic capturing the data
/// assigned to the component.
#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
pub struct ConjugateComponent<X, Fx, Pr>
where
    X: LaceDatum,
    Fx: LaceLikelihood<X>,
    Fx::Stat: LaceStat,
    Pr: ConjugatePrior<X, Fx>,
    Pr::LnPpCache: Send + Sync + Clone + std::fmt::Debug,
{
    #[serde(bound(deserialize = "Fx: serde::de::DeserializeOwned"))]
    pub fx: Fx,
    #[serde(bound(deserialize = "Fx: serde::de::DeserializeOwned"))]
    pub stat: Fx::Stat,
    #[serde(skip)]
    pub ln_pp_cache: OnceCell<Pr::LnPpCache>,
}

impl<X, Fx, Pr> AccumScore<X> for ConjugateComponent<X, Fx, Pr>
where
    X: LaceDatum,
    Fx: LaceLikelihood<X>,
    Fx::Stat: LaceStat,
    Pr: ConjugatePrior<X, Fx>,
    Pr::LnPpCache: Send + Sync + Clone + std::fmt::Debug,
{
    fn accum_score(&self, scores: &mut [f64], container: &SparseContainer<X>) {
        self.fx.accum_score(scores, container)
    }

    // fn accum_score_par(
    //     &self,
    //     mut scores: &mut [f64],
    //     xs: &[X],
    //     present: &[bool],
    // ) {
    //     self.fx.accum_score_par(&mut scores, &xs, &present)
    // }
}

impl<X, Fx, Pr> ConjugateComponent<X, Fx, Pr>
where
    X: LaceDatum,
    Fx: LaceLikelihood<X>,
    Fx::Stat: LaceStat,
    Pr: ConjugatePrior<X, Fx>,
    Pr::LnPpCache: Send + Sync + Clone + std::fmt::Debug,
{
    /// Create a new ConjugateComponent with no observations
    #[inline]
    pub fn new(fx: Fx) -> Self {
        let stat = fx.empty_suffstat();
        ConjugateComponent {
            fx,
            stat,
            ln_pp_cache: OnceCell::new(),
        }
    }

    /// Return the observations
    #[inline]
    pub fn obs(&self) -> DataOrSuffStat<X, Fx> {
        DataOrSuffStat::SuffStat(&self.stat)
    }

    #[inline]
    pub fn reset_ln_pp_cache(&mut self) {
        self.ln_pp_cache = OnceCell::new()
    }

    #[inline]
    pub fn ln_pp_cache(&self, prior: &Pr) -> &Pr::LnPpCache {
        self.ln_pp_cache
            .get_or_init(|| prior.ln_pp_cache(&self.obs()))
    }
}

impl<X, Fx, Pr> Rv<X> for ConjugateComponent<X, Fx, Pr>
where
    X: LaceDatum,
    Fx: LaceLikelihood<X>,
    Fx::Stat: LaceStat,
    Pr: ConjugatePrior<X, Fx>,
    Pr::LnPpCache: Send + Sync + Clone + std::fmt::Debug,
{
    fn ln_f(&self, x: &X) -> f64 {
        self.fx.ln_f(x)
    }

    fn draw<R: Rng>(&self, mut rng: &mut R) -> X {
        self.fx.draw(&mut rng)
    }

    fn sample<R: Rng>(&self, n: usize, mut rng: &mut R) -> Vec<X> {
        self.fx.sample(n, &mut rng)
    }
}

impl<X, Fx, Pr> Mode<X> for ConjugateComponent<X, Fx, Pr>
where
    X: LaceDatum,
    Fx: LaceLikelihood<X> + Mode<X>,
    Fx::Stat: LaceStat,
    Pr: ConjugatePrior<X, Fx>,
    Pr::LnPpCache: Send + Sync + Clone + std::fmt::Debug,
{
    fn mode(&self) -> Option<X> {
        self.fx.mode()
    }
}

impl<X, Fx, Pr> Entropy for ConjugateComponent<X, Fx, Pr>
where
    X: LaceDatum,
    Fx: LaceLikelihood<X> + Entropy,
    Fx::Stat: LaceStat,
    Pr: ConjugatePrior<X, Fx>,
    Pr::LnPpCache: Send + Sync + Clone + std::fmt::Debug,
{
    fn entropy(&self) -> f64 {
        self.fx.entropy()
    }
}

impl<X, Fx, Pr> SuffStat<X> for ConjugateComponent<X, Fx, Pr>
where
    X: LaceDatum,
    Fx: LaceLikelihood<X>,
    Fx::Stat: LaceStat,
    Pr: ConjugatePrior<X, Fx>,
    Pr::LnPpCache: Send + Sync + Clone + std::fmt::Debug,
{
    fn n(&self) -> usize {
        self.stat.n()
    }

    fn observe(&mut self, x: &X) {
        self.reset_ln_pp_cache();
        self.stat.observe(x);
    }

    fn forget(&mut self, x: &X) {
        self.reset_ln_pp_cache();
        self.stat.forget(x);
    }
}

impl<X, Fx, Pr> From<ConjugateComponent<X, Fx, Pr>> for Component
where
    X: LaceDatum,
    Fx: LaceLikelihood<X>,
    Fx::Stat: LaceStat,
    Pr: ConjugatePrior<X, Fx>,
    Pr::LnPpCache: Send + Sync + Clone + std::fmt::Debug,
{
    fn from(cpnt: ConjugateComponent<X, Fx, Pr>) -> Component {
        cpnt.fx.into()
    }
}