114 lines
3.4 KiB
Python
114 lines
3.4 KiB
Python
import os
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import pandas as pd
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import numpy as np
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from sklearn.preprocessing import StandardScaler
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from sklearn.model_selection import train_test_split
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def load_data(name):
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df = pd.read_csv(name)
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return df
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def normalize_data(df):
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scaler = StandardScaler()
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df["Amount"] = scaler.fit_transform(df["Amount"].values.reshape(-1, 1))
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return df
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def create_undersample_data(df):
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# Determine the number of instances in the minority class
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fraud_count = len(df[df.Class == 1])
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fraud_indices = np.array(df[df.Class == 1].index)
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# Select indices corresponding to majority class instances
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normal_indices = df[df.Class == 0].index
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# Randomly sample the same number of instances from the majority class
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random_normal_indices = np.random.choice(normal_indices, fraud_count, replace=False)
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random_normal_indices = np.array(random_normal_indices)
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# Combine indices of both classes
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undersample_indice = np.concatenate([fraud_indices, random_normal_indices])
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# Undersample dataset
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undersample_data = df.iloc[undersample_indice, :]
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X_undersample = undersample_data.iloc[:, undersample_data.columns != "Class"]
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y_undersample = undersample_data.iloc[:, undersample_data.columns == "Class"]
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return undersample_data, X_undersample, y_undersample
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def split_undersample_data(X_undersample, y_undersample):
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X_train_undersample, X_test_undersample, y_train_undersample, y_test_undersample = (
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train_test_split(X_undersample, y_undersample, test_size=0.3, random_state=0)
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)
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return (
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X_train_undersample,
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X_test_undersample,
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y_train_undersample,
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y_test_undersample,
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)
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def save_undersample_data(
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undersample_data,
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X_train_undersample,
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X_test_undersample,
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y_train_undersample,
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y_test_undersample,
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):
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undersample_data.to_csv("data/undersample_data.csv", index=False)
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X_train_undersample.to_csv("data/X_train_undersample.csv", index=False)
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X_test_undersample.to_csv("data/X_test_undersample.csv", index=False)
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y_train_undersample.to_csv("data/y_train_undersample.csv", index=False)
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y_test_undersample.to_csv("data/y_test_undersample.csv", index=False)
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def split_whole_data(df):
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X = df.iloc[:, df.columns != "Class"]
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y = df.iloc[:, df.columns == "Class"]
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X_train, X_test, y_train, y_test = train_test_split(
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X, y, test_size=0.3, random_state=0
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)
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return X_train, X_test, y_train, y_test
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def save_whole_data(df, X_train, X_test, y_train, y_test):
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df.to_csv("data/creditcard.csv", index=False)
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X_train.to_csv("data/X_train.csv", index=False)
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X_test.to_csv("data/X_test.csv", index=False)
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y_train.to_csv("data/y_train.csv", index=False)
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y_test.to_csv("data/y_test.csv", index=False)
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def main():
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os.makedirs("data", exist_ok=True)
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df = load_data("creditcard.csv")
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df = normalize_data(df)
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undersample_data, X_undersample, y_undersample = create_undersample_data(df)
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X_train_undersample, X_test_undersample, y_train_undersample, y_test_undersample = (
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split_undersample_data(X_undersample, y_undersample)
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)
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save_undersample_data(
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undersample_data,
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X_train_undersample,
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X_test_undersample,
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y_train_undersample,
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y_test_undersample,
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)
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X_train, X_test, y_train, y_test = split_whole_data(df)
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save_whole_data(df, X_train, X_test, y_train, y_test)
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if __name__ == "__main__":
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main()
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