调用sklearn库实现对鸢尾花数据的分类,采用逻辑回归分类方法,并计算以下多分类性能评价指标(两种方式):混淆矩阵、准确率、精确率、召回率、F1值、分类报告,并绘制PR曲线与ROC曲线。
时间: 2023-08-18 15:06:15 浏览: 75
好的,我来回答你的问题。
首先,需要加载鸢尾花数据集,代码如下:
```python
from sklearn.datasets import load_iris
iris = load_iris()
X = iris.data
y = iris.target
```
然后将数据集分为训练集和测试集:
```python
from sklearn.model_selection import train_test_split
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.3, random_state=42)
```
接下来,使用逻辑回归分类器进行分类:
```python
from sklearn.linear_model import LogisticRegression
clf = LogisticRegression(random_state=42)
clf.fit(X_train, y_train)
y_pred = clf.predict(X_test)
```
现在,我们可以进行多分类性能评价了。
1. 混淆矩阵
```python
from sklearn.metrics import confusion_matrix
confusion_matrix(y_test, y_pred)
```
2. 准确率、精确率、召回率、F1值、分类报告
```python
from sklearn.metrics import accuracy_score, precision_score, recall_score, f1_score, classification_report
print("Accuracy:", accuracy_score(y_test, y_pred))
print("Precision:", precision_score(y_test, y_pred, average='weighted'))
print("Recall:", recall_score(y_test, y_pred, average='weighted'))
print("F1 score:", f1_score(y_test, y_pred, average='weighted'))
print(classification_report(y_test, y_pred))
```
3. PR曲线与ROC曲线
```python
import matplotlib.pyplot as plt
from sklearn.metrics import plot_precision_recall_curve, plot_roc_curve
plot_precision_recall_curve(clf, X_test, y_test)
plt.show()
plot_roc_curve(clf, X_test, y_test)
plt.show()
```
这就是使用sklearn库实现对鸢尾花数据的分类,并计算多分类性能评价指标的过程,希望对你有所帮助。