tf_idf_vectorizer/vectorizer/
mod.rs

1pub mod corpus;
2pub mod tfidf;
3pub mod token;
4pub mod serde;
5pub mod evaluate;
6
7use std::sync::Arc;
8
9use indexmap::IndexSet;
10use num::Num;
11use ::serde::{Deserialize, Serialize};
12
13use crate::{utils::{math::vector::{ZeroSpVec, ZeroSpVecTrait}, normalizer::DeNormalizer}, vectorizer::{corpus::Corpus, tfidf::{DefaultTFIDFEngine, TFIDFEngine}, token::TokenFrequency}};
14use ahash::RandomState;
15
16#[derive(Debug)]
17pub struct TFIDFVectorizer<N = f32, K = String, E = DefaultTFIDFEngine>
18where
19    N: Num + Copy,
20    E: TFIDFEngine<N>,
21{
22    /// Document's TF Vector
23    pub documents: Vec<TFVector<N, K>>,
24    /// TF Vector's token dimension sample
25    pub token_dim_sample: IndexSet<String, RandomState>,
26    /// Corpus reference
27    pub corpus_ref: Arc<Corpus>,
28    /// IDF Vector
29    pub idf: IDFVector<N>,
30    _marker: std::marker::PhantomData<E>,
31}
32
33#[derive(Debug, Serialize, Deserialize)]
34pub struct TFVector<N, K>
35where
36    N: Num + Copy,
37{
38    /// TF Vector
39    /// use sparse vector
40    pub tf_vec: ZeroSpVec<N>,
41    /// sum of tokens of this document
42    pub token_sum: u64,
43    /// denormalize number for this document
44    /// for reverse calculation to get token counts from tf values
45    pub denormalize_num: f64,
46    /// Document ID
47    pub key: K,
48}
49
50impl<N, K> TFVector<N, K>
51where
52    N: Num + Copy,
53{
54    pub fn shrink_to_fit(&mut self) {
55        self.tf_vec.shrink_to_fit();
56    }
57}
58
59#[derive(Debug, Serialize, Deserialize)]
60pub struct IDFVector<N>
61where
62    N: Num,
63{
64    /// IDF Vector it is not sparse because it is mostly filled
65    pub idf_vec: Vec<N>,
66    /// denormalize number for idf
67    pub denormalize_num: f64,
68    /// latest entropy
69    pub latest_entropy: u64,
70    /// document count
71    pub doc_num: u64,
72}
73
74impl <N> IDFVector<N>
75where
76    N: Num,
77{
78    pub fn new() -> Self {
79        Self {
80            idf_vec: Vec::new(),
81            denormalize_num: 1.0,
82            latest_entropy: 0,
83            doc_num: 0,
84        }
85    }
86}
87
88impl <N, K, E> TFIDFVectorizer<N, K, E>
89where
90    N: Num + Copy,
91    E: TFIDFEngine<N>,
92{
93    /// Create a new TFIDFVectorizer instance
94    pub fn new(corpus_ref: Arc<Corpus>) -> Self {
95        let mut instance = Self {
96            documents: Vec::new(),
97            token_dim_sample: IndexSet::with_hasher(RandomState::new()),
98            corpus_ref,
99            idf: IDFVector::new(),
100            _marker: std::marker::PhantomData,
101        };
102        instance.re_calc_idf();
103        instance
104    }
105
106    /// set corpus reference
107    /// and recalculate idf
108    pub fn set_corpus_ref(&mut self, corpus_ref: Arc<Corpus>) {
109        self.corpus_ref = corpus_ref;
110        self.re_calc_idf();
111    }
112
113    /// Corpusに変更があればIDFを再計算する
114    pub fn update_idf(&mut self) {
115        if self.corpus_ref.get_gen_num() != self.idf.latest_entropy {
116            self.re_calc_idf();
117        }
118        // 更新がなければ何もしない
119    }
120
121    /// CorpusからIDFを再計算する
122    fn re_calc_idf(&mut self) {
123        self.idf.latest_entropy = self.corpus_ref.get_gen_num();
124        self.idf.doc_num = self.corpus_ref.get_doc_num();
125        (self.idf.idf_vec, self.idf.denormalize_num) = E::idf_vec(&self.corpus_ref, &self.token_dim_sample)
126    }
127}
128
129impl <N, K, E> TFIDFVectorizer<N, K, E>
130where
131    N: Num + Copy,
132    E: TFIDFEngine<N>,
133{
134    /// Add a document
135    /// The immediately referenced Corpus is also updated
136    pub fn add_doc(&mut self, doc_id: K, doc: &TokenFrequency) {
137        let token_sum = doc.token_sum();
138        // ドキュメントのトークンをコーパスに追加
139        self.add_corpus(doc);
140        // 新語彙を差分追加 (O(|doc_vocab|))
141        for tok in doc.token_set_ref_str() {
142            if !self.token_dim_sample.contains(tok) {
143                self.token_dim_sample.insert(tok.to_string());
144            }
145        }
146
147        let (tf_vec, denormalize_num) = E::tf_vec(doc, &self.token_dim_sample);
148        let mut doc = TFVector {
149            tf_vec,
150            token_sum,
151            denormalize_num,
152            key: doc_id,
153        };
154        doc.shrink_to_fit();
155        self.documents.push(doc);
156    }
157
158    /// Get TFVector by document ID
159    pub fn get_tf(&self, key: &K) -> Option<&TFVector<N, K>>
160    where
161        K: PartialEq,
162    {
163        self.documents.iter().find(|doc| &doc.key == key)
164    }
165
166    /// Get TokenFrequency by document ID
167    /// If quantized, there may be some error
168    /// Words not included in the corpus are ignored
169    pub fn get_tf_into_token_freq(&self, key: &K) -> Option<TokenFrequency>
170    where
171        K: PartialEq,
172        N: Into<f64>,
173    {
174        if let Some(tf_vec) = self.get_tf(key) {
175            let mut token_freq = TokenFrequency::new();
176            tf_vec.tf_vec.raw_iter().for_each(|(idx, val)| {
177                if let Some(token) = self.token_dim_sample.get_index(idx) {
178                    let val_f64: f64 = (*val).into();
179                    let token_num: f64 = tf_vec.token_sum.denormalize(tf_vec.denormalize_num) * val_f64;
180                    token_freq.set_token_count(token, token_num as u64);
181                } // out of range is ignored
182            });
183            Some(token_freq)
184        } else {
185            None
186        }
187    }
188
189    /// add document to corpus
190    /// update the referenced corpus
191    fn add_corpus(&mut self, doc: &TokenFrequency) {
192        // add document to corpus
193        self.corpus_ref.add_set(&doc.token_set_ref_str());
194    }
195}
tf_idf_vectorizer/vectorizer/mod.rs

tf_idf_vectorizer/vectorizer/
mod.rs
