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    LY的博客:sklearn学习笔记之svm

    作者:[db:作者] 时间:2021-08-10 09:52

    支持向量机:

    # -*- coding: utf-8 -*-
    import sklearn
    from sklearn.svm import SVC
    import matplotlib.pyplot as plt
    from sklearn.model_selection import train_test_split
    from sklearn import datasets
    import pandas as pd
    import numpy
    
    
    def getData_1():
    
        iris = datasets.load_iris()
        X = iris.data   #样本特征矩阵,150*4矩阵,每行一个样本,每个样本维度是4
        y = iris.target #样本类别矩阵,150维行向量,每个元素代表一个样本的类别
    
    
        df1=pd.DataFrame(X, columns =['SepalLengthCm','SepalWidthCm','PetalLengthCm','PetalWidthCm'])
        df1['target']=y
    
        return df1
    
    df=getData_1()
    
    
    X_train, X_test, y_train, y_test = train_test_split(df.iloc[:,0:3],df['target'], test_size=0.3, random_state=42)
    print X_train, X_test, y_train, y_test
    
    
    model = SVC(C=1.0, kernel='rbf', gamma='auto')
    """参数
    ---
        C:误差项的惩罚参数C
        gamma: 核相关系数。浮点数,If gamma is ‘auto’ then 1/n_features will be used instead.
    """
    
    
    model.fit(X_train,y_train)
    predict=model.predict(X_test)
    print predict
    print y_test.values
    
    print 'SVC分类:{:.3f}'.format(model.score(X_test, y_test))
    

    结果:

    [1 0 2 1 1 0 1 2 1 1 2 0 0 0 0 1 2 1 1 2 0 2 0 2 2 2 2 2 0 0 0 0 1 0 0 2 1
    ?0 0 0 2 1 1 0 0]
    [1 0 2 1 1 0 1 2 1 1 2 0 0 0 0 1 2 1 1 2 0 2 0 2 2 2 2 2 0 0 0 0 1 0 0 2 1
    ?0 0 0 2 1 1 0 0]

    SVC分类:1.000

    准确度惊人的100%......,比线性回归和朴素贝叶斯分类高很多。。。

    cs