• Python-根据成绩分析是否继续深造


    案例:该数据集的是一个关于每个学生成绩的数据集,接下来我们对该数据集进行分析,判断学生是否适合继续深造

    数据集特征展示

    1     GRE 成绩 (290 to 340)
    2     TOEFL 成绩(92 to 120)
    3     学校等级 (1 to 5)
    4     自身的意愿 (1 to 5)
    5     推荐信的力度 (1 to 5)
    6     CGPA成绩 (6.8 to 9.92)
    7     是否有研习经验 (0 or 1)
    8     读硕士的意向 (0.34 to 0.97)

    1.导入包

    import numpy as np
    import pandas as pd
    import matplotlib.pyplot as plt
    import seaborn as sns
    import os,sys

    2.导入并查看数据集

    df = pd.read_csv("D:\machine-learning\score\Admission_Predict.csv",sep = ",")
    print('There are ',len(df.columns),'columns')
    for c in df.columns:
        sys.stdout.write(str(c)+', '
    There are  9 columns
    Serial No., GRE Score, TOEFL Score, University Rating, SOP, LOR , CGPA, Research, Chance of Admit , 
    一共有9列特征
    df.info()
    <class 'pandas.core.frame.DataFrame'>
    RangeIndex: 400 entries, 0 to 399
    Data columns (total 9 columns):
    Serial No.           400 non-null int64
    GRE Score            400 non-null int64
    TOEFL Score          400 non-null int64
    University Rating    400 non-null int64
    SOP                  400 non-null float64
    LOR                  400 non-null float64
    CGPA                 400 non-null float64
    Research             400 non-null int64
    Chance of Admit      400 non-null float64
    dtypes: float64(4), int64(5)
    memory usage: 28.2 KB

    数据集信息:
      1.数据有9个特征,分别是学号,GRE分数,托福分数,学校等级,SOP,LOR,CGPA,是否参加研习,进修的几率
      2.数据集中没有空值
      3.一共有400条数据
    # 整理列名称
    df = df.rename(columns={'Chance of Admit ':'Chance of Admit'})
    # 显示前5列数据
    df.head()

    3.查看每个特征的相关性

    fig,ax = plt.subplots(figsize=(10,10))
    sns.heatmap(df.corr(),ax=ax,annot=True,linewidths=0.05,fmt='.2f',cmap='magma')
    plt.show()

      结论:1.最有可能影响是否读硕士的特征是GRE,CGPA,TOEFL成绩

         2.影响相对较小的特征是LOR,SOP,和Research

     4.数据可视化,双变量分析

       4.1 进行Research的人数

    print("Not Having Research:",len(df[df.Research == 0]))
    print("Having Research:",len(df[df.Research == 1]))
    y = np.array([len(df[df.Research == 0]),len(df[df.Research == 1])])
    x = np.arange(2)
    plt.bar(x,y)
    plt.title("Research Experience")
    plt.xlabel("Canditates")
    plt.ylabel("Frequency")
    plt.xticks(x,('Not having research','Having research'))
    plt.show()

      结论:进行research的人数是219,本科没有research人数是181

      4.2 学生的托福成绩

    y = np.array([df['TOEFL Score'].min(),df['TOEFL Score'].mean(),df['TOEFL Score'].max()])
    x = np.arange(3)
    plt.bar(x,y)
    plt.title('TOEFL Score')
    plt.xlabel('Level')
    plt.ylabel('TOEFL Score')
    plt.xticks(x,('Worst','Average','Best'))
    plt.show()

      结论:最低分92分,最高分满分,进修学生的英语成绩很不错

      4.3 GRE成绩

    df['GRE Score'].plot(kind='hist',bins=200,figsize=(6,6))
    plt.title('GRE Score')
    plt.xlabel('GRE Score')
    plt.ylabel('Frequency')
    plt.show()

      结论:310和330的分值的学生居多

      4.4 CGPA和学校等级的关系

    plt.scatter(df['University Rating'],df['CGPA'])
    plt.title('CGPA Scores for University ratings')
    plt.xlabel('University Rating')
    plt.ylabel('CGPA')
    plt.show()

      结论:学校越好,学生的GPA可能就越高

      4.5 GRE成绩和CGPA的关系

    plt.scatter(df['GRE Score'],df['CGPA'])
    plt.title('CGPA for GRE Scores')
    plt.xlabel('GRE Score')
    plt.ylabel('CGPA')
    plt.show()

      结论:GPA基点越高,GRE分数越高,2者的相关性很大

      4.6 托福成绩和GRE成绩的关系

    df[df['CGPA']>=8.5].plot(kind='scatter',x='GRE Score',y='TOEFL Score',color='red')
    plt.xlabel('GRE Score')
    plt.ylabel('TOEFL Score')
    plt.title('CGPA >= 8.5')
    plt.grid(True)
    plt.show()

      结论:多数情况下GRE和托福成正相关,但是GRE分数高,托福一定高。

      4.6 学校等级和是否读硕士的关系

    s = df[df['Chance of Admit'] >= 0.75]['University Rating'].value_counts().head(5)
    plt.title('University Ratings of Candidates with an 75% acceptance chance')
    s.plot(kind='bar',figsize=(20,10),cmap='Pastel1')
    plt.xlabel('University Rating')
    plt.ylabel('Candidates')
    plt.show()

      结论:排名靠前的学校的学生,进修的可能性更大

      4.7 SOP和GPA的关系

    plt.scatter(df['CGPA'],df['SOP'])
    plt.xlabel('CGPA')
    plt.ylabel('SOP')
    plt.title('SOP for CGPA')
    plt.show()

      结论: GPA很高的学生,选择读硕士的自我意愿更强烈

      4.8 SOP和GRE的关系

    plt.scatter(df['GRE Score'],df['SOP'])
    plt.xlabel('GRE Score')
    plt.ylabel('SOP')
    plt.title('SOP for GRE Score')
    plt.show()

      结论:读硕士意愿强的学生,GRE分数较高

    5.模型

      5.1 准备数据集

    # 读取数据集
    df = pd.read_csv('D:\machine-learning\score\Admission_Predict.csv',sep=',')
    
    serialNO = df['Serial No.'].values
    
    df.drop(['Serial No.'],axis=1,inplace=True)
    df = df.rename(columns={'Chance of Admit ':'Chance of Admit'})
    
    # 分割数据集
    y = df['Chance of Admit'].values
    x = df.drop(['Chance of Admit'],axis=1)
    
    from sklearn.model_selection import train_test_split
    x_train,x_test,y_train,y_test = train_test_split(x,y,test_size=0.2,random_state=42)
    # 归一化数据
    from sklearn.preprocessing import MinMaxScaler
    scaleX = MinMaxScaler(feature_range=[0,1])
    x_train[x_train.columns] = scaleX.fit_transform(x_train[x_train.columns])
    x_test[x_test.columns] = scaleX.fit_transform(x_test[x_test.columns])

      5.2 回归

        5.2.1 线性回归

    from sklearn.linear_model import LinearRegression
    
    lr = LinearRegression()
    lr.fit(x_train,y_train)
    y_head_lr = lr.predict(x_test)
    
    print('Real value of y_test[1]: '+str(y_test[1]) + ' -> predict value: ' + str(lr.predict(x_test.iloc[[1],:])))
    print('Real value of y_test[2]: '+str(y_test[2]) + ' -> predict value: ' + str(lr.predict(x_test.iloc[[2],:])))
    
    from sklearn.metrics import r2_score
    print('r_square score: ',r2_score(y_test,y_head_lr))
    y_head_lr_train = lr.predict(x_train)
    print('r_square score(train data):',r2_score(y_train,y_head_lr_train))

        5.2.2 随机森林回归

    from sklearn.ensemble import RandomForestRegressor
    
    rfr = RandomForestRegressor(n_estimators=100,random_state=42)
    rfr.fit(x_train,y_train)
    y_head_rfr = rfr.predict(x_test)
    
    print('Real value of y_test[1]: '+str(y_test[1]) + ' -> predict value: ' + str(rfr.predict(x_test.iloc[[1],:])))
    print('Real value of y_test[2]: '+str(y_test[2]) + ' -> predict value: ' + str(rfr.predict(x_test.iloc[[2],:])))
    
    from sklearn.metrics import r2_score
    print('r_square score: ',r2_score(y_test,y_head_rfr))
    y_head_rfr_train = rfr.predict(x_train)
    print('r_square score(train data):',r2_score(y_train,y_head_rfr_train))

        5.2.3 决策树回归

    from sklearn.tree import DecisionTreeRegressor
    
    dt = DecisionTreeRegressor(random_state=42)
    dt.fit(x_train,y_train)
    y_head_dt = dt.predict(x_test)
    
    print('Real value of y_test[1]: '+str(y_test[1]) + ' -> predict value: ' + str(dt.predict(x_test.iloc[[1],:])))
    print('Real value of y_test[2]: '+str(y_test[2]) + ' -> predict value: ' + str(dt.predict(x_test.iloc[[2],:])))
    
    from sklearn.metrics import r2_score
    print('r_square score: ',r2_score(y_test,y_head_dt))
    y_head_dt_train = dt.predict(x_train)
    print('r_square score(train data):',r2_score(y_train,y_head_dt_train))

        5.2.4 三种回归方法比较

    y = np.array([r2_score(y_test,y_head_lr),r2_score(y_test,y_head_rfr),r2_score(y_test,y_head_dt)])
    x = np.arange(3)
    plt.bar(x,y)
    plt.title('Comparion of Regression Algorithms')
    plt.xlabel('Regression')
    plt.ylabel('r2_score')
    plt.xticks(x,("LinearRegression","RandomForestReg.","DecisionTreeReg."))
    plt.show()

        结论 : 回归算法中,线性回归的性能更优

        5.2.5 三种回归方法与实际值的比较

    ​red = plt.scatter(np.arange(0,80,5),y_head_lr[0:80:5],color='red')
    blue = plt.scatter(np.arange(0,80,5),y_head_rfr[0:80:5],color='blue')
    green = plt.scatter(np.arange(0,80,5),y_head_dt[0:80:5],color='green')
    black = plt.scatter(np.arange(0,80,5),y_test[0:80:5],color='black')
    plt.title('Comparison of Regression Algorithms')
    plt.xlabel('Index of candidate')
    plt.ylabel('Chance of admit')
    plt.legend([red,blue,green,black],['LR','RFR','DT','REAL'])
    plt.show()

        结论:在数据集中有70%的候选人有可能读硕士,从上图来看还有些点没有很好的得到预测

      5.3 分类算法

        5.3.1 准备数据

    df = pd.read_csv('D:\machine-learning\score\Admission_Predict.csv',sep=',')
    
    SerialNO = df['Serial No.'].values
    df.drop(['Serial No.'],axis=1,inplace=True)
    
    df = df.rename(columns={'Chance of Admit ':'Chance of Admit'})
    y = df['Chance of Admit'].values
    x = df.drop(['Chance of Admit'],axis=1)
    
    
    from sklearn.model_selection import train_test_split
    x_train,x_test,y_train,y_test = train_test_split(x,y,test_size=0.2,random_state=42)
    
    from sklearn.preprocessing import MinMaxScaler
    scaleX = MinMaxScaler(feature_range=[0,1])
    x_train[x_train.columns] = scaleX.fit_transform(x_train[x_train.columns])
    x_test[x_test.columns] = scaleX.fit_transform(x_test[x_test.columns])
    
    # 如果chance >0.8, chance of admit 就是1,否则就是0
    y_train_01 = [1 if each > 0.8 else 0 for each in y_train]
    y_test_01 = [1 if each > 0.8 else 0 for each in y_test]
    
    y_train_01 = np.array(y_train_01)
    y_test_01 = np.array(y_test_01)

        5.3.2 逻辑回归

    from sklearn.linear_model import LogisticRegression
    
    lrc = LogisticRegression()
    lrc.fit(x_train,y_train_01)
    print('score: ',lrc.score(x_test,y_test_01))
    print('Real value of y_test_01[1]: '+str(y_test_01[1]) + ' -> predict value: ' + str(lrc.predict(x_test.iloc[[1],:])))
    print('Real value of y_test_01[2]: '+str(y_test_01[2]) + ' -> predict value: ' + str(lrc.predict(x_test.iloc[[2],:])))
    
    from sklearn.metrics import confusion_matrix
    cm_lrc = confusion_matrix(y_test_01,lrc.predict(x_test))
    
    f,ax = plt.subplots(figsize=(5,5))
    sns.heatmap(cm_lrc,annot=True,linewidths=0.5,linecolor='red',fmt='.0f',ax=ax)
    plt.title('Test for Test dataset')
    plt.xlabel('predicted y values')
    plt.ylabel('real y value')
    plt.show()
    
    from sklearn.metrics import recall_score,precision_score,f1_score
    print('precision_score is : ',precision_score(y_test_01,lrc.predict(x_test)))
    print('recall_score is : ',recall_score(y_test_01,lrc.predict(x_test)))
    print('f1_score is : ',f1_score(y_test_01,lrc.predict(x_test)))
    
    # Test for Train Dataset:
    
    cm_lrc_train = confusion_matrix(y_train_01,lrc.predict(x_train))
    f,ax = plt.subplots(figsize=(5,5))
    sns.heatmap(cm_lrc_train,annot=True,linewidths=0.5,linecolor='blue',fmt='.0f',ax=ax)
    plt.title('Test for Train dataset')
    plt.xlabel('predicted y values')
    plt.ylabel('real y value')
    plt.show()

        结论:1.通过混淆矩阵,逻辑回归算法在训练集样本上,有23个分错的样本,有72人想进一步读硕士

           2.在测试集上有7个分错的样本 

        5.3.3 支持向量机(SVM)

    from sklearn.svm import SVC
    
    svm = SVC(random_state=1,kernel='rbf')
    svm.fit(x_train,y_train_01)
    print('score: ',svm.score(x_test,y_test_01))
    print('Real value of y_test_01[1]: '+str(y_test_01[1]) + ' -> predict value: ' + str(svm.predict(x_test.iloc[[1],:])))
    print('Real value of y_test_01[2]: '+str(y_test_01[2]) + ' -> predict value: ' + str(svm.predict(x_test.iloc[[2],:])))
    
    from sklearn.metrics import confusion_matrix
    cm_svm = confusion_matrix(y_test_01,svm.predict(x_test))
    
    f,ax = plt.subplots(figsize=(5,5))
    sns.heatmap(cm_svm,annot=True,linewidths=0.5,linecolor='red',fmt='.0f',ax=ax)
    plt.title('Test for Test dataset')
    plt.xlabel('predicted y values')
    plt.ylabel('real y value')
    plt.show()
    
    from sklearn.metrics import recall_score,precision_score,f1_score
    print('precision_score is : ',precision_score(y_test_01,svm.predict(x_test)))
    print('recall_score is : ',recall_score(y_test_01,svm.predict(x_test)))
    print('f1_score is : ',f1_score(y_test_01,svm.predict(x_test)))
    
    # Test for Train Dataset:
    
    cm_svm_train = confusion_matrix(y_train_01,svm.predict(x_train))
    f,ax = plt.subplots(figsize=(5,5))
    sns.heatmap(cm_svm_train,annot=True,linewidths=0.5,linecolor='blue',fmt='.0f',ax=ax)
    plt.title('Test for Train dataset')
    plt.xlabel('predicted y values')
    plt.ylabel('real y value')
    plt.show()

     

        结论:1.通过混淆矩阵,SVM算法在训练集样本上,有22个分错的样本,有70人想进一步读硕士

           2.在测试集上有8个分错的样本

        5.3.4 朴素贝叶斯

    from sklearn.naive_bayes import GaussianNB
    
    nb = GaussianNB()
    nb.fit(x_train,y_train_01)
    print('score: ',nb.score(x_test,y_test_01))
    print('Real value of y_test_01[1]: '+str(y_test_01[1]) + ' -> predict value: ' + str(nb.predict(x_test.iloc[[1],:])))
    print('Real value of y_test_01[2]: '+str(y_test_01[2]) + ' -> predict value: ' + str(nb.predict(x_test.iloc[[2],:])))
    
    from sklearn.metrics import confusion_matrix
    cm_nb = confusion_matrix(y_test_01,nb.predict(x_test))
    
    f,ax = plt.subplots(figsize=(5,5))
    sns.heatmap(cm_nb,annot=True,linewidths=0.5,linecolor='red',fmt='.0f',ax=ax)
    plt.title('Test for Test dataset')
    plt.xlabel('predicted y values')
    plt.ylabel('real y value')
    plt.show()
    
    from sklearn.metrics import recall_score,precision_score,f1_score
    print('precision_score is : ',precision_score(y_test_01,nb.predict(x_test)))
    print('recall_score is : ',recall_score(y_test_01,nb.predict(x_test)))
    print('f1_score is : ',f1_score(y_test_01,nb.predict(x_test)))
    
    # Test for Train Dataset:
    
    cm_nb_train = confusion_matrix(y_train_01,nb.predict(x_train))
    f,ax = plt.subplots(figsize=(5,5))
    sns.heatmap(cm_nb_train,annot=True,linewidths=0.5,linecolor='blue',fmt='.0f',ax=ax)
    plt.title('Test for Train dataset')
    plt.xlabel('predicted y values')
    plt.ylabel('real y value')
    plt.show()

        结论:1.通过混淆矩阵,朴素贝叶斯算法在训练集样本上,有20个分错的样本,有78人想进一步读硕士

           2.在测试集上有7个分错的样本

        5.3.5 随机森林分类器

    from sklearn.ensemble import RandomForestClassifier
    
    rfc = RandomForestClassifier(n_estimators=100,random_state=1)
    rfc.fit(x_train,y_train_01)
    print('score: ',rfc.score(x_test,y_test_01))
    print('Real value of y_test_01[1]: '+str(y_test_01[1]) + ' -> predict value: ' + str(rfc.predict(x_test.iloc[[1],:])))
    print('Real value of y_test_01[2]: '+str(y_test_01[2]) + ' -> predict value: ' + str(rfc.predict(x_test.iloc[[2],:])))
    
    from sklearn.metrics import confusion_matrix
    cm_rfc = confusion_matrix(y_test_01,rfc.predict(x_test))
    
    f,ax = plt.subplots(figsize=(5,5))
    sns.heatmap(cm_rfc,annot=True,linewidths=0.5,linecolor='red',fmt='.0f',ax=ax)
    plt.title('Test for Test dataset')
    plt.xlabel('predicted y values')
    plt.ylabel('real y value')
    plt.show()
    
    from sklearn.metrics import recall_score,precision_score,f1_score
    print('precision_score is : ',precision_score(y_test_01,rfc.predict(x_test)))
    print('recall_score is : ',recall_score(y_test_01,rfc.predict(x_test)))
    print('f1_score is : ',f1_score(y_test_01,rfc.predict(x_test)))
    
    # Test for Train Dataset:
    
    cm_rfc_train = confusion_matrix(y_train_01,rfc.predict(x_train))
    f,ax = plt.subplots(figsize=(5,5))
    sns.heatmap(cm_rfc_train,annot=True,linewidths=0.5,linecolor='blue',fmt='.0f',ax=ax)
    plt.title('Test for Train dataset')
    plt.xlabel('predicted y values')
    plt.ylabel('real y value')
    plt.show()

         结论:1.通过混淆矩阵,随机森林算法在训练集样本上,有0个分错的样本,有88人想进一步读硕士

            2.在测试集上有5个分错的样本

        5.3.6 决策树分类器

    from sklearn.tree import DecisionTreeClassifier
    
    dtc = DecisionTreeClassifier(criterion='entropy',max_depth=3)
    dtc.fit(x_train,y_train_01)
    print('score: ',dtc.score(x_test,y_test_01))
    print('Real value of y_test_01[1]: '+str(y_test_01[1]) + ' -> predict value: ' + str(dtc.predict(x_test.iloc[[1],:])))
    print('Real value of y_test_01[2]: '+str(y_test_01[2]) + ' -> predict value: ' + str(dtc.predict(x_test.iloc[[2],:])))
    
    from sklearn.metrics import confusion_matrix
    cm_dtc = confusion_matrix(y_test_01,dtc.predict(x_test))
    
    f,ax = plt.subplots(figsize=(5,5))
    sns.heatmap(cm_dtc,annot=True,linewidths=0.5,linecolor='red',fmt='.0f',ax=ax)
    plt.title('Test for Test dataset')
    plt.xlabel('predicted y values')
    plt.ylabel('real y value')
    plt.show()
    
    from sklearn.metrics import recall_score,precision_score,f1_score
    print('precision_score is : ',precision_score(y_test_01,dtc.predict(x_test)))
    print('recall_score is : ',recall_score(y_test_01,dtc.predict(x_test)))
    print('f1_score is : ',f1_score(y_test_01,dtc.predict(x_test)))
    
    # Test for Train Dataset:
    
    cm_dtc_train = confusion_matrix(y_train_01,dtc.predict(x_train))
    f,ax = plt.subplots(figsize=(5,5))
    sns.heatmap(cm_dtc_train,annot=True,linewidths=0.5,linecolor='blue',fmt='.0f',ax=ax)
    plt.title('Test for Train dataset')
    plt.xlabel('predicted y values')
    plt.ylabel('real y value')
    plt.show()

        结论:1.通过混淆矩阵,决策树算法在训练集样本上,有20个分错的样本,有78人想进一步读硕士

            2.在测试集上有7个分错的样本

        5.3.7 K临近分类器

    from sklearn.neighbors import KNeighborsClassifier
    
    scores = []
    for each in range(1,50):
        knn_n = KNeighborsClassifier(n_neighbors = each)
        knn_n.fit(x_train,y_train_01)
        scores.append(knn_n.score(x_test,y_test_01))
        
    plt.plot(range(1,50),scores)
    plt.xlabel('k')
    plt.ylabel('Accuracy')
    plt.show()
    
    
    knn = KNeighborsClassifier(n_neighbors=7)
    knn.fit(x_train,y_train_01)
    print('score 7 : ',knn.score(x_test,y_test_01))
    print('Real value of y_test_01[1]: '+str(y_test_01[1]) + ' -> predict value: ' + str(knn.predict(x_test.iloc[[1],:])))
    print('Real value of y_test_01[2]: '+str(y_test_01[2]) + ' -> predict value: ' + str(knn.predict(x_test.iloc[[2],:])))
    
    from sklearn.metrics import confusion_matrix
    cm_knn = confusion_matrix(y_test_01,knn.predict(x_test))
    
    f,ax = plt.subplots(figsize=(5,5))
    sns.heatmap(cm_knn,annot=True,linewidths=0.5,linecolor='red',fmt='.0f',ax=ax)
    plt.title('Test for Test dataset')
    plt.xlabel('predicted y values')
    plt.ylabel('real y value')
    plt.show()
    
    from sklearn.metrics import recall_score,precision_score,f1_score
    print('precision_score is : ',precision_score(y_test_01,knn.predict(x_test)))
    print('recall_score is : ',recall_score(y_test_01,knn.predict(x_test)))
    print('f1_score is : ',f1_score(y_test_01,knn.predict(x_test)))
    
    # Test for Train Dataset:
    
    cm_knn_train = confusion_matrix(y_train_01,knn.predict(x_train))
    f,ax = plt.subplots(figsize=(5,5))
    sns.heatmap(cm_knn_train,annot=True,linewidths=0.5,linecolor='blue',fmt='.0f',ax=ax)
    plt.title('Test for Train dataset')
    plt.xlabel('predicted y values')
    plt.ylabel('real y value')
    plt.show()

        结论:1.通过混淆矩阵,K临近算法在训练集样本上,有22个分错的样本,有71人想进一步读硕士

            2.在测试集上有7个分错的样本

       5.3.8 分类器比较

    y = np.array([lrc.score(x_test,y_test_01),svm.score(x_test,y_test_01),nb.score(x_test,y_test_01),
                  dtc.score(x_test,y_test_01),rfc.score(x_test,y_test_01),knn.score(x_test,y_test_01)])
    x = np.arange(6)
    plt.bar(x,y)
    plt.title('Comparison of Classification Algorithms')
    plt.xlabel('Classification')
    plt.ylabel('Score')
    plt.xticks(x,("LogisticReg.","SVM","GNB","Dec.Tree","Ran.Forest","KNN"))
    plt.show()

         

        结论:随机森林和朴素贝叶斯二者的预测值都比较高

      5.4 聚类算法

        5.4.1 准备数据

    df = pd.read_csv('D:\machine-learning\score\Admission_Predict.csv',sep=',')
    df = df.rename(columns={'Chance of Admit ':'Chance of Admit'})
    serialNo = df['Serial No.']
    df.drop(['Serial No.'],axis=1,inplace=True)
    df = (df - np.min(df)) / (np.max(df)-np.min(df))
    y = df['Chance of Admit']
    x = df.drop(['Chance of Admit'],axis=1)

           5.4.2 降维

    from sklearn.decomposition import PCA
    
    pca = PCA(n_components=1,whiten=True)
    pca.fit(x)
    x_pca = pca.transform(x)
    x_pca = x_pca.reshape(400)
    dictionary = {'x':x_pca,'y':y}
    data = pd.DataFrame(dictionary)
    print('pca data:',data.head())
    
    print()
    
    print('orin data:',df.head())

        5.4.3 K均值聚类

    from sklearn.cluster import KMeans
    
    wcss = []
    for k in range(1,15):
        kmeans = KMeans(n_clusters=k)
        kmeans.fit(x)
        wcss.append(kmeans.inertia_)
    plt.plot(range(1,15),wcss)
    plt.xlabel('Kmeans')
    plt.ylabel('WCSS')
    plt.show()
    
    df["Serial No."] = serialNo
    kmeans = KMeans(n_clusters=3)
    clusters_knn = kmeans.fit_predict(x)
    df['label_kmeans'] = clusters_knn
    
    
    plt.scatter(df[df.label_kmeans == 0 ]["Serial No."],df[df.label_kmeans == 0]['Chance of Admit'],color = "red")
    plt.scatter(df[df.label_kmeans == 1 ]["Serial No."],df[df.label_kmeans == 1]['Chance of Admit'],color = "blue")
    plt.scatter(df[df.label_kmeans == 2 ]["Serial No."],df[df.label_kmeans == 2]['Chance of Admit'],color = "green")
    plt.title("K-means Clustering")
    plt.xlabel("Candidates")
    plt.ylabel("Chance of Admit")
    plt.show()
    
    plt.scatter(data.x[df.label_kmeans == 0 ],data[df.label_kmeans == 0].y,color = "red")
    plt.scatter(data.x[df.label_kmeans == 1 ],data[df.label_kmeans == 1].y,color = "blue")
    plt.scatter(data.x[df.label_kmeans == 2 ],data[df.label_kmeans == 2].y,color = "green")
    plt.title("K-means Clustering")
    plt.xlabel("X")
    plt.ylabel("Chance of Admit")
    plt.show()

      

        结论:数据集分成三个类别,一部分学生是决定继续读硕士,一部分放弃,还有一部分学生的比较犹豫,但是深造的可能性较大

        5.4.4 层次聚类

    from scipy.cluster.hierarchy import linkage,dendrogram
    
    merg = linkage(x,method='ward')
    dendrogram(merg,leaf_rotation=90)
    plt.xlabel('data points')
    plt.ylabel('euclidean distance')
    plt.show()
    
    from sklearn.cluster import AgglomerativeClustering
    
    hiyerartical_cluster = AgglomerativeClustering(n_clusters=3,affinity='euclidean',linkage='ward')
    clusters_hiyerartical = hiyerartical_cluster.fit_predict(x)
    df['label_hiyerartical'] = clusters_hiyerartical
    
    plt.scatter(df[df.label_hiyerartical == 0 ]["Serial No."],df[df.label_hiyerartical == 0]['Chance of Admit'],color = "red")
    plt.scatter(df[df.label_hiyerartical == 1 ]["Serial No."],df[df.label_hiyerartical == 1]['Chance of Admit'],color = "blue")
    plt.scatter(df[df.label_hiyerartical == 2 ]["Serial No."],df[df.label_hiyerartical == 2]['Chance of Admit'],color = "green")
    plt.title('Hierarchical Clustering')
    plt.xlabel('Candidates')
    plt.ylabel('Chance of Admit')
    plt.show()
    
    plt.scatter(data[df.label_hiyerartical == 0].x,data.y[df.label_hiyerartical==0],color='red')
    plt.scatter(data[df.label_hiyerartical == 1].x,data.y[df.label_hiyerartical==1],color='blue')
    plt.scatter(data[df.label_hiyerartical == 2].x,data.y[df.label_hiyerartical==2],color='green')
    plt.title('Hierarchical Clustering')
    plt.xlabel('X')
    plt.ylabel('Chance of Admit')
    plt.show()

        结论:从层次聚类的结果中,可以看出和K均值聚类的结果一致,只不过确定了聚类k的取值3

    结论:通过本词入门数据集的训练,可以掌握

         1.一些特征的展示的方法

              2.如何调用sklearn 的API

              3.如何取比较不同模型之间的好坏

    代码+数据集:https://github.com/Mounment/python-data-analyze/tree/master/kaggle/score

    如果有用的话,记得打一个星星,谢谢

          



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  • 原文地址:https://www.cnblogs.com/luhuajun/p/10361463.html
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