From 671ef1efea9d71058b2662fed230859223db7d5d Mon Sep 17 00:00:00 2001
From: Alex Moreo <alejandro.moreo@isti.cnr.it>
Date: Tue, 30 Nov 2021 15:55:32 +0100
Subject: [PATCH] first commit

---
 eDiscovery/main.py | 80 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)
 create mode 100644 eDiscovery/main.py

diff --git a/eDiscovery/main.py b/eDiscovery/main.py
new file mode 100644
index 0000000..3921e03
--- /dev/null
+++ b/eDiscovery/main.py
@@ -0,0 +1,80 @@
+from sklearn.base import BaseEstimator
+from sklearn.calibration import CalibratedClassifierCV
+from sklearn.linear_model import LogisticRegression
+
+import quapy as qp
+from method.base import BaseQuantifier
+from quapy.data import LabelledCollection
+from quapy.method.aggregative import EMQ, ClassifyAndCount, PACC
+from quapy import functional as F
+import numpy as np
+
+
+def split_from_index(collection:LabelledCollection, index:np.ndarray):
+    in_index_set = set(index)
+    out_index_set = set(range(len(collection))) - in_index_set
+    out_index = np.asarray(list(out_index_set), dtype=int)
+    return collection.sampling_from_index(index), collection.sampling_from_index(out_index)
+
+
+def relevance_sampling_index(pool:LabelledCollection, classifier:BaseEstimator, k:int):
+    prob = classifier.predict_proba(pool.instances)[:, 1].flatten()
+    top_relevant_idx = np.argsort(-prob)[:k]
+    return top_relevant_idx
+
+
+def recall(train_prev, pool_prev, train_len, pool_len):
+    nD = train_len + pool_len
+    pTr = train_len / nD
+    pPool = pool_len / nD
+    recall = train_prev[1] * pTr / (train_prev[1] * pTr + pool_prev[1] * pPool)
+    return recall
+
+
+data = qp.datasets.fetch_reviews('imdb', tfidf=True, min_df=5)
+# collection = data.training + data.test
+collection = data.training.sampling(10000, 0.75)
+nD = len(collection)
+
+# initial labelled data selection
+init_nD = 100
+init_prev = 0.5
+idx = collection.sampling_index(init_nD, init_prev)
+train, pool = split_from_index(collection, idx)
+
+k = 50
+recall_target = 0.95
+
+# Q = EMQ(CalibratedClassifierCV(LogisticRegression()))
+# Q = ClassifyAndCount(LogisticRegression())
+Q = PACC(LogisticRegression())
+
+i = 0
+while True:
+    Q.fit(train)
+    pool_p_hat = Q.quantify(pool.instances)
+    tr_p = train.prevalence()
+    te_p = pool.prevalence()
+    nDtr = len(train)
+    nDte = len(pool)
+
+    r_hat = recall(tr_p, pool_p_hat, nDtr, nDte)
+    r = recall(tr_p, te_p, nDtr, nDte)
+    r_error = abs(r_hat-r)
+
+    proc_percent = 100*nDtr/nD
+
+    print(f'{i}\t [{proc_percent:.2f}%] tr-prev={F.strprev(tr_p)} te-prev={F.strprev(te_p)} te-estim={F.strprev(pool_p_hat)} R={r:.3f} Rhat={r_hat:.3f} E={r_error:.3f}')
+    # if r_hat >= recall_target:
+    if proc_percent > 95:
+        break
+
+    top_relevant_idx = relevance_sampling_index(pool, Q.learner, k)
+    selected, pool = split_from_index(pool, top_relevant_idx)
+    train = train + selected
+
+    i += 1
+
+
+
+