下面列举了常见的机器学习算法的sklearn接口。
这是目录
1、LinearRegression
from sklearn.datasets import load_iris
from sklearn.model_selection import train_test_split
from sklearn.linear_model import LinearRegression #线性回归
iris = load_iris() #加载数据集
X,y = iris.data,iris.target #(150,4)
train_X,test_X,train_y,test_y = train_test_split(X,y,test_size=0.2,random_state=2020) #划分训练集和测试集
model = LinearRegression() #线性回归模型
model.fit(train_X,train_y) #模型训练
predict_y = model.predict(test_X) #模型预测
score = model.score(test_X,test_y) #模型评估,R2 score
print(predict_y)
print(test_y)
print(score)
2、LogisticRegression
from sklearn.datasets import load_iris
from sklearn.model_selection import train_test_split
from sklearn.linear_model import LogisticRegression
iris = load_iris()
X,y = iris.data, iris.target
train_X,test_X,train_y,test_y = train_test_split(X,y,test_size=0.2,random_state=2020)
model = LogisticRegression()
model.fit(train_X,train_y)
predict_y = model.predict(test_X) #模型预测,predict是训练后返回预测结果,是标签值。
#predict_y_prob = model.predict_proba(test_X)#predict_proba返回的是一个 n 行 k 列的数组, 第 i 行 第 j 列上的数值是模型预测 第 i 个预测样本为某个标签的概率,并且每一行的概率和为1。
score = model.score(test_X,test_y) #模型评估,R2 score
print(predict_y)
#print(predict_y_prob)
print(test_y)
print(score)
3、KNeighborsClassifier
from sklearn.datasets import load_iris
from sklearn.model_selection import train_test_split
from sklearn.neighbors import KNeighborsClassifier
iris = load_iris()
X,y = iris.data, iris.target
train_X,test_X,train_y,test_y = train_test_split(X,y,test_size=0.2,random_state=2020)
model = KNeighborsClassifier(n_neighbors=1)
model.fit(train_X,train_y)
predict_y = model.predict(test_X) #模型预测
#predict_y_prob = model.predict_proba(test_X)#输出每一类的概率[为0类的概率,为1类的概率,为2类的概率]
score = model.score(test_X,test_y) #模型评估,R2 score