如何在 python 中用图例和 AUC 分数在一个图中绘制多条 ROC 曲线？

Question

我正在构建 2 个模型。

模型 1

modelgb = GradientBoostingClassifier()
modelgb.fit(x_train,y_train)
predsgb = modelgb.predict_proba(x_test)[:,1]
metrics.roc_auc_score(y_test,predsgb, average='macro', sample_weight=None)

模型 2

model = LogisticRegression()
model = model.fit(x_train,y_train)
predslog = model.predict_proba(x_test)[:,1]
metrics.roc_auc_score(y_test,predslog, average='macro', sample_weight=None)

我如何在一个图中绘制两条 ROC 曲线，并为每个模型提供 AUC 分数的图例和文本？

Answer 1

尝试根据您的数据进行调整：

from sklearn import metrics
import numpy as np
import matplotlib.pyplot as plt

plt.figure(0).clf()

pred = np.random.rand(1000)
label = np.random.randint(2, size=1000)
fpr, tpr, thresh = metrics.roc_curve(label, pred)
auc = metrics.roc_auc_score(label, pred)
plt.plot(fpr,tpr,label="data 1, auc="+str(auc))

pred = np.random.rand(1000)
label = np.random.randint(2, size=1000)
fpr, tpr, thresh = metrics.roc_curve(label, pred)
auc = metrics.roc_auc_score(label, pred)
plt.plot(fpr,tpr,label="data 2, auc="+str(auc))

plt.legend(loc=0)

Answer 2

只需将模型添加到列表中，即可在一个图中绘制多条 ROC 曲线。希望这对你有用！

from sklearn.linear_model import LogisticRegression
from sklearn.ensemble import GradientBoostingClassifier
from sklearn import metrics
import matplotlib.pyplot as plt

plt.figure()

# Add the models to the list that you want to view on the ROC plot
models = [
{
    'label': 'Logistic Regression',
    'model': LogisticRegression(),
},
{
    'label': 'Gradient Boosting',
    'model': GradientBoostingClassifier(),
}
]

# Below for loop iterates through your models list
for m in models:
    model = m['model'] # select the model
    model.fit(x_train, y_train) # train the model
    y_pred=model.predict(x_test) # predict the test data
# Compute False postive rate, and True positive rate
    fpr, tpr, thresholds = metrics.roc_curve(y_test, model.predict_proba(x_test)[:,1])
# Calculate Area under the curve to display on the plot
    auc = metrics.roc_auc_score(y_test,model.predict(x_test))
# Now, plot the computed values
    plt.plot(fpr, tpr, label='%s ROC (area = %0.2f)' % (m['label'], auc))
# Custom settings for the plot 
plt.plot([0, 1], [0, 1],'r--')
plt.xlim([0.0, 1.0])
plt.ylim([0.0, 1.05])
plt.xlabel('1-Specificity(False Positive Rate)')
plt.ylabel('Sensitivity(True Positive Rate)')
plt.title('Receiver Operating Characteristic')
plt.legend(loc="lower right")
plt.show()   # Display

Answer 3

from sklearn.metrics import plot_roc_curve

classifiers = [log_reg, decision_tree, decision_forest]
ax = plt.gca()
for i in classifiers:
    plot_roc_curve(i, X_test, y_test, ax=ax)

Answer 4

像这样...

#ROC Curve
from sklearn.metrics import roc_curve
y_pred_prob1 = classifier1.predict_proba(X_test)[:,1]
fpr1 , tpr1, thresholds1 = roc_curve(Y_test, y_pred_prob1)

y_pred_prob2 = classifier2.predict_proba(X_test)[:,1]
fpr2 , tpr2, thresholds2 = roc_curve(Y_test, y_pred_prob2)


y_pred_prob3 = classifier3.predict_proba(X_test)[:,1]
fpr3 , tpr3, thresholds3 = roc_curve(Y_test, y_pred_prob3)

y_pred_prob4 = classifier4.predict_proba(X_test)[:,1]
fpr4 , tpr4, thresholds4 = roc_curve(Y_test, y_pred_prob4)


plt.plot([0,1],[0,1], 'k--')
plt.plot(fpr1, tpr1, label= "Linear")
plt.plot(fpr2, tpr2, label= "Poly")
plt.plot(fpr3, tpr3, label= "RBF")
plt.plot(fpr4, tpr4, label= "Sigmoid")
plt.legend()
plt.xlabel("FPR")
plt.ylabel("TPR")
plt.title('Receiver Operating Characteristic')
plt.show()

Answer 5

from sklearn.metrics import plot_roc_curve


fig = plot_roc_curve( clf, x_train_bow, y_train)
fig = plot_roc_curve( clf, x_test_bow, y_test, ax = fig.ax_)
fig.figure_.suptitle("ROC curve comparison")
plt.show()

基本上 plot_roc_curve 函数绘制分类器的 roc_curve。因此，如果我们在没有指定 ax 参数的情况下使用 plot_roc_curve 两次，它将绘制两个图形。所以在这里我们将第一个图存储在图形变量中并访问它的轴并提供给下一个 plot_roc_curve 函数，以便仅显示第一个图的轴的图。

如何在 python 中用图例和 AUC 分数在一个图中绘制多条 ROC 曲线？

How to plot multiple ROC curves in one plot with legend and AUC scores in python?

python

plot

roc

auc