Train a field of study (domain) classification of sentences on the MAG dataset¶

SciBERT achieves an F1-score of 0.6571 on this dataset. This notebook shows that better results can be achieved without even using transformers.

In [1]:

import json
from typing import Tuple
from great_ai.utilities import clean, parallel_map
from tqdm.cli import tqdm


def preprocess(line: str) -> Tuple[str, str]:
    data_point = json.loads(line)

    return (clean(data_point["text"], convert_to_ascii=True), data_point["label"])


with open("mag/train.txt", encoding="utf-8") as f:
    training_data = list(tqdm(parallel_map(preprocess, f.readlines())))

X_train = [d[0] for d in training_data]
y_train = [d[1] for d in training_data]


with open("mag/test.txt", encoding="utf-8") as f:
    test_data = list(tqdm(parallel_map(preprocess, f.readlines())))

X_test = [d[0] for d in test_data]
y_test = [d[1] for d in test_data]

import json from typing import Tuple from great_ai.utilities import clean, parallel_map from tqdm.cli import tqdm def preprocess(line: str) -> Tuple[str, str]: data_point = json.loads(line) return (clean(data_point["text"], convert_to_ascii=True), data_point["label"]) with open("mag/train.txt", encoding="utf-8") as f: training_data = list(tqdm(parallel_map(preprocess, f.readlines()))) X_train = [d[0] for d in training_data] y_train = [d[1] for d in training_data] with open("mag/test.txt", encoding="utf-8") as f: test_data = list(tqdm(parallel_map(preprocess, f.readlines()))) X_test = [d[0] for d in test_data] y_test = [d[1] for d in test_data]

84000it [00:09, 8647.60it/s] 
22399it [00:03, 6368.63it/s]

In [2]:

import pandas as pd
from collections import Counter
import plotly.express as px


df = pd.DataFrame(Counter(y_train).most_common(), columns=["domain", "count"])
px.bar(df, "domain", "count", width=1200, height=400).show()

import pandas as pd from collections import Counter import plotly.express as px df = pd.DataFrame(Counter(y_train).most_common(), columns=["domain", "count"]) px.bar(df, "domain", "count", width=1200, height=400).show()

In [3]:

from sklearn.naive_bayes import MultinomialNB
from sklearn.pipeline import Pipeline
from sklearn.feature_extraction.text import TfidfVectorizer


def create_pipeline() -> Pipeline:
    return Pipeline(
        steps=[
            ("vectorizer", TfidfVectorizer(sublinear_tf=True)),
            ("classifier", MultinomialNB()),
        ]
    )

from sklearn.naive_bayes import MultinomialNB from sklearn.pipeline import Pipeline from sklearn.feature_extraction.text import TfidfVectorizer def create_pipeline() -> Pipeline: return Pipeline( steps=[ ("vectorizer", TfidfVectorizer(sublinear_tf=True)), ("classifier", MultinomialNB()), ] )

In [4]:

from sklearn.model_selection import GridSearchCV

optimisation_pipeline = GridSearchCV(
    create_pipeline(),
    {
        "vectorizer__min_df": [5, 20, 100],
        "vectorizer__max_df": [0.05, 0.1],
        "classifier__alpha": [0.5, 1],
        "classifier__fit_prior": [True, False],
    },
    scoring="f1_macro",
    cv=3,
    n_jobs=-1,
    verbose=1,
)
optimisation_pipeline.fit(X_train, y_train)

results = pd.DataFrame(optimisation_pipeline.cv_results_)
results.sort_values("rank_test_score")

from sklearn.model_selection import GridSearchCV optimisation_pipeline = GridSearchCV( create_pipeline(), { "vectorizer__min_df": [5, 20, 100], "vectorizer__max_df": [0.05, 0.1], "classifier__alpha": [0.5, 1], "classifier__fit_prior": [True, False], }, scoring="f1_macro", cv=3, n_jobs=-1, verbose=1, ) optimisation_pipeline.fit(X_train, y_train) results = pd.DataFrame(optimisation_pipeline.cv_results_) results.sort_values("rank_test_score")

Fitting 3 folds for each of 24 candidates, totalling 72 fits

Out[4]:

	mean_fit_time	std_fit_time	mean_score_time	std_score_time	param_classifier__alpha	param_classifier__fit_prior	param_vectorizer__max_df	param_vectorizer__min_df	params	split0_test_score	split1_test_score	split2_test_score	mean_test_score	std_test_score	rank_test_score
12	1.227354	0.011710	0.652844	0.040511	1	True	0.05	5	{'classifier__alpha': 1, 'classifier__fit_prio...	0.677283	0.670398	0.665671	0.671118	0.004768	1
15	1.279783	0.037969	0.634761	0.068606	1	True	0.1	5	{'classifier__alpha': 1, 'classifier__fit_prio...	0.676970	0.670244	0.666123	0.671112	0.004470	2
18	1.332854	0.171405	0.743611	0.109792	1	False	0.05	5	{'classifier__alpha': 1, 'classifier__fit_prio...	0.675678	0.669321	0.665305	0.670101	0.004271	3
21	1.253222	0.072134	0.612344	0.016771	1	False	0.1	5	{'classifier__alpha': 1, 'classifier__fit_prio...	0.675569	0.669482	0.665225	0.670092	0.004245	4
3	1.472035	0.080849	0.654935	0.044302	0.5	True	0.1	5	{'classifier__alpha': 0.5, 'classifier__fit_pr...	0.675225	0.668912	0.665652	0.669930	0.003974	5
0	1.380641	0.054306	0.739966	0.053385	0.5	True	0.05	5	{'classifier__alpha': 0.5, 'classifier__fit_pr...	0.675264	0.668781	0.665394	0.669813	0.004095	6
9	1.284987	0.113903	0.696876	0.003757	0.5	False	0.1	5	{'classifier__alpha': 0.5, 'classifier__fit_pr...	0.674199	0.668005	0.664456	0.668887	0.004026	7
6	1.291148	0.101837	0.686561	0.083989	0.5	False	0.05	5	{'classifier__alpha': 0.5, 'classifier__fit_pr...	0.673996	0.668048	0.664572	0.668872	0.003891	8
13	1.268873	0.042412	0.645649	0.022738	1	True	0.05	20	{'classifier__alpha': 1, 'classifier__fit_prio...	0.656459	0.647433	0.644864	0.649585	0.004972	9
16	1.147120	0.009335	0.599006	0.045637	1	True	0.1	20	{'classifier__alpha': 1, 'classifier__fit_prio...	0.656196	0.646960	0.645436	0.649530	0.004754	10
4	1.186988	0.057330	0.642233	0.078248	0.5	True	0.1	20	{'classifier__alpha': 0.5, 'classifier__fit_pr...	0.654424	0.644690	0.644991	0.648035	0.004519	11
1	1.413231	0.153288	0.765960	0.099535	0.5	True	0.05	20	{'classifier__alpha': 0.5, 'classifier__fit_pr...	0.654622	0.644901	0.644425	0.647983	0.004699	12
19	1.193013	0.079000	0.691768	0.027448	1	False	0.05	20	{'classifier__alpha': 1, 'classifier__fit_prio...	0.655125	0.645586	0.643166	0.647959	0.005163	13
22	1.043618	0.098733	0.450375	0.061660	1	False	0.1	20	{'classifier__alpha': 1, 'classifier__fit_prio...	0.654254	0.645409	0.643514	0.647726	0.004680	14
7	1.301459	0.062143	0.660748	0.056054	0.5	False	0.05	20	{'classifier__alpha': 0.5, 'classifier__fit_pr...	0.652727	0.643691	0.642749	0.646389	0.004498	15
10	1.433934	0.155240	0.636608	0.024064	0.5	False	0.1	20	{'classifier__alpha': 0.5, 'classifier__fit_pr...	0.652290	0.642975	0.643421	0.646229	0.004290	16
14	1.325535	0.073539	0.672542	0.085835	1	True	0.05	100	{'classifier__alpha': 1, 'classifier__fit_prio...	0.587097	0.577411	0.580170	0.581560	0.004075	17
17	1.237677	0.070063	0.651091	0.102538	1	True	0.1	100	{'classifier__alpha': 1, 'classifier__fit_prio...	0.585713	0.577197	0.580763	0.581224	0.003492	18
2	1.394873	0.105286	0.637073	0.041708	0.5	True	0.05	100	{'classifier__alpha': 0.5, 'classifier__fit_pr...	0.586346	0.576987	0.579852	0.581062	0.003915	19
5	1.270732	0.013414	0.620984	0.025393	0.5	True	0.1	100	{'classifier__alpha': 0.5, 'classifier__fit_pr...	0.585634	0.576217	0.580320	0.580723	0.003855	20
20	1.177219	0.039633	0.586308	0.044247	1	False	0.05	100	{'classifier__alpha': 1, 'classifier__fit_prio...	0.581096	0.572833	0.576280	0.576736	0.003389	21
8	1.165583	0.046999	0.603675	0.031774	0.5	False	0.05	100	{'classifier__alpha': 0.5, 'classifier__fit_pr...	0.580841	0.572391	0.575731	0.576321	0.003475	22
23	0.907388	0.121543	0.354655	0.023775	1	False	0.1	100	{'classifier__alpha': 1, 'classifier__fit_prio...	0.579769	0.572373	0.576699	0.576280	0.003034	23
11	1.210845	0.041339	0.653606	0.028117	0.5	False	0.1	100	{'classifier__alpha': 0.5, 'classifier__fit_pr...	0.579743	0.571607	0.576352	0.575901	0.003337	24

In [5]:

from sklearn import set_config

set_config(display="diagram")

classifier = create_pipeline()
classifier.set_params(**optimisation_pipeline.best_params_)
classifier.fit(X_train, y_train)

from sklearn import set_config set_config(display="diagram") classifier = create_pipeline() classifier.set_params(**optimisation_pipeline.best_params_) classifier.fit(X_train, y_train)

Out[5]:

Pipeline(steps=[('vectorizer',
                 TfidfVectorizer(max_df=0.05, min_df=5, sublinear_tf=True)),
                ('classifier', MultinomialNB(alpha=1))])

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In [6]:

from sklearn import metrics
import matplotlib.pyplot as plt

y_predicted = classifier.predict(X_test)

%matplotlib inline
plt.rcParams["figure.figsize"] = (30, 15)
plt.rcParams["figure.facecolor"] = "white"
plt.rcParams["font.size"] = 12
plt.rcParams["axes.xmargin"] = 0

print(metrics.classification_report(y_test, y_predicted, digits=4))
metrics.ConfusionMatrixDisplay.from_predictions(
    y_true=y_test,
    y_pred=y_predicted,
    xticks_rotation="vertical",
    normalize="pred",
    values_format=".2f",
)
None

from sklearn import metrics import matplotlib.pyplot as plt y_predicted = classifier.predict(X_test) %matplotlib inline plt.rcParams["figure.figsize"] = (30, 15) plt.rcParams["figure.facecolor"] = "white" plt.rcParams["font.size"] = 12 plt.rcParams["axes.xmargin"] = 0 print(metrics.classification_report(y_test, y_predicted, digits=4)) metrics.ConfusionMatrixDisplay.from_predictions( y_true=y_test, y_pred=y_predicted, xticks_rotation="vertical", normalize="pred", values_format=".2f", ) None

              precision    recall  f1-score   support

    business     0.6412    0.7258    0.6808      3198
   economics     0.6635    0.7146    0.6881      3189
   geography     0.7461    0.6791    0.7111      3207
    medicine     0.8806    0.9021    0.8912      3187
    politics     0.5563    0.5895    0.5724      3169
  psychology     0.7654    0.6811    0.7208      3252
   sociology     0.5165    0.4698    0.4921      3197

    accuracy                         0.6803     22399
   macro avg     0.6814    0.6803    0.6795     22399
weighted avg     0.6817    0.6803    0.6796     22399

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Last update: July 11, 2022