python_93040206/admin_site/test/nri.py

import pandas as pd
from sklearn.linear_model import LogisticRegression
from sklearn.metrics import classification_report
from sklearn.metrics.regression import net_reclassification_index
import matplotlib.pyplot as plt

# 加载数据
snp_data = pd.read_csv('snp_data.csv')  # 假设SNP数据已保存在CSV文件中
# other_data = pd.read_csv('other_data.csv')  # 假设其他特征数据已保存在CSV文件中
target = pd.read_csv('target.csv')  # 假设目标数据已保存在CSV文件中

# 合并数据
data = pd.concat([snp_data, target], axis=1)

# 划分训练集和测试集
train_data = data.sample(frac=0.8, random_state=1)
test_data = data.drop(train_data.index)

# 训练基线模型和改进模型
X_train = train_data.drop('target', axis=1)
y_train = train_data['target']
X_test = test_data.drop('target', axis=1)
y_test = test_data['target']

base_model = LogisticRegression(random_state=1)
base_model.fit(X_train, y_train)
improved_model = LogisticRegression(random_state=1, solver='liblinear', penalty='l1')
improved_model.fit(X_train, y_train)

# 使用模型进行分类并计算NRI指标
base_proba = base_model.predict_proba(X_test)
improved_proba = improved_model.predict_proba(X_test)
nri = net_reclassification_index(y_test, base_proba[:, 1], improved_proba[:, 1])

# 输出NRI指标
print('NRI:', nri)

# 可视化NRI指标
nri_df = pd.DataFrame({'Model': ['Baseline', 'Improved'], 'NRI': [0, nri]})
plt.bar(nri_df['Model'], nri_df['NRI'], color=['#1f77b4', '#ff7f0e'])
plt.ylim([0, 1])
plt.xlabel('Model')
plt.ylabel('NRI')
plt.title('Net Reclassification Improvement')
plt.show()