R_Studio(学生成绩)使用主成分分析实现属性规约

　　对11_1_4.csv成绩表进行主成分分析处理

　　

setwd('D:\data')

list.files()

#读取数据
dat=read.csv(file="11_1_4.csv",header=TRUE)
dat=dat[,-c(1,2,10,11)]

#主成分分析
PCA=princomp(dat,cor=F)
names(PCA)#查看输出项

(PCA$sdev)^2#主成分特征根
summary(PCA)#主成分贡献率
PCA$loadings#主成分载荷      
PCA$scores#主成分得分

> summary(PCA)#主成分贡献率
Importance of components:
                          Comp.1    Comp.2     Comp.3     Comp.4     Comp.5     Comp.6     Comp.7
Standard deviation     21.923097 13.877129 11.2585833 9.08290162 7.12019143 5.87691397 5.25241336  #主成分的标准差
Proportion of Variance  0.482904  0.193489  0.1273575 0.08289078 0.05093782 0.03470209 0.02771882  #方差的贡献率
Cumulative Proportion   0.482904  0.676393  0.8037505 0.88664127 0.93757908 0.97228118 1.00000000  #方差的累积贡献率

 

> PCA$loadings#主成分载荷

Loadings:
                 Comp.1 Comp.2 Comp.3 Comp.4 Comp.5 Comp.6 Comp.7
JAVA程序设计      0.236  0.163                0.297  0.909       
电子商务技术      0.623 -0.756  0.124         0.118              
计算机维护与维修         0.104                0.190 -0.133  0.960
计算机组成原理    0.470  0.338  0.208 -0.306 -0.719              
数据库系统原理    0.365  0.314  0.335  0.761  0.131 -0.234       
算法设计与分析    0.372  0.153 -0.894  0.110        -0.105 -0.126
大学英语A_4       0.239  0.393  0.155 -0.553  0.572 -0.287 -0.221

               Comp.1 Comp.2 Comp.3 Comp.4 Comp.5 Comp.6 Comp.7
SS loadings     1.000  1.000  1.000  1.000  1.000  1.000  1.000
Proportion Var  0.143  0.143  0.143  0.143  0.143  0.143  0.143
Cumulative Var  0.143  0.286  0.429  0.571  0.714  0.857  1.000

> PCA$scores#主成分得分
           Comp.1      Comp.2       Comp.3      Comp.4      Comp.5      Comp.6       Comp.7
 [1,]  33.3196037  17.6874355  -0.25422380 -11.2669060   4.2917495  -1.7364204   4.97518007
 [2,]  31.1801767  14.1593983  -4.47470827  -7.0283584   6.4786703  -5.8908663   7.45630606
 [3,]  16.0593623   4.1733395   4.73087356   3.8211303   5.0571100  -2.4575435   3.28774257
 [4,]  18.4599795   6.8838756  -5.17888938  -3.5337153  -3.5324890   9.0664813 -10.53284043
 [5,]  22.6257727  -5.2588625   9.25342354  -0.7271976   9.8075163   8.4440318  -2.74254542
 [6,]  18.4583765   0.3841284  -5.83949272  -8.1471985 -13.7079196  -6.2410719  -3.88663198
 [7,]  20.7765859  13.6381355  -1.96535180   7.0825406  11.4998414   3.8088176  -6.24709551
 [8,]  22.4055982   1.2572326  -4.52725913   8.5461387  -5.8650063   3.1370173   5.43043952
 [9,]  10.6507844  10.4129351  15.42304832   4.4685204   1.1673139   8.1402877  -9.46484450
[10,]  17.1639629  -2.9525391 -10.01258904 -25.4490785  -5.4754708 -13.5277187  -7.95516018
[11,]  17.7945634   8.4024604  -0.35035882   2.3099044 -10.0253564   6.9582191   2.35849100
[12,]  12.8598877  -0.5588604  12.91817330  -2.2976186   5.7661594   0.3122876   1.63729804
[13,]  17.8084340  -3.0194490  -6.51371177   2.1379239  -4.3093249  -0.2923455  -2.14479586
[14,]  10.4585027   1.0417386 -19.73650352  14.2034399   1.8029565   6.4274103  -8.10728416
[15,]  10.3192625  -4.8219566  -3.60217599  -4.0807410   9.1303336   2.1788406  -0.47648506
[16,]  19.4722336  -9.0230062  13.96055565  -3.0505762  16.4767485  -0.0768518   1.97413948
[17,]  12.4466032   3.6624606  11.86842261  -2.2940459  -5.3363913   2.9385003  12.01728038
[18,]  10.9412050  -5.2512180  12.77385227   0.1711016   5.8379586   1.8466416  -7.84034045
[19,]  20.2156694 -11.9257596  -4.89824057   4.2539217   1.2212099  -1.3598156   0.69586378
[20,]   7.5757204   1.4629122  12.45201823   1.3380320 -11.4475596  -3.0560369  -0.33679014
[21,]   2.7560708   9.2670628  12.12499946   8.2058762  -6.6679381  -1.8767783   1.75044570
[22,]   6.9386608  21.9442175  16.71159245   2.4286736  -0.8955840  -6.6829971  -4.72743757
[23,]  -9.9243741   0.4757100   0.01573284   1.4254642   2.4706595  -3.8905899   2.61108720
[24,]   6.5950893   3.7321278  -8.91241929  -0.5066062   6.3637581   1.2706868   1.10666607
[25,]  16.2275862  -4.7775620 -13.76590352 -22.8140031   5.2334105   9.4658474   3.59374787
[26,]  -1.6370774  16.7224036  11.47807300   1.3839942   0.1871615  -3.8104935  -2.65749127
[27,]  -4.9984010   6.7262848   9.33017015   9.4159721 -11.9826050  -1.9271300  -2.70926180
[28,]  -0.9466044  -4.9963382 -13.44043198   6.8435895   7.0608288  -2.0568204  -6.36663646
[29,]  -6.9405262   9.3086749  -4.25783374  13.8646433   0.9253015 -12.7755734  -0.51105509
[30,]   1.7219892  -5.6298414 -10.69930010  13.6120593  -5.2090180 -10.0628742  -4.78383632
[31,]  -0.3541851  12.2312177  -6.08951913  10.4920885  -7.2794460   3.1028452   4.27513314
[32,]  -4.3581531  -5.9643460  -7.16475122   6.4932550  -5.1895961  -1.7878238   2.16402149
[33,] -14.4453722  -0.1044177   1.61962685   9.0343576  -2.1145786   7.1296350   6.88736228
[34,]  -3.8559156 -20.4106594   2.79158832   0.3726180  -4.4280421  -0.6170102   4.28772644
[35,]  13.6221594  -7.3733618  -4.65438509  -6.9531488 -10.0671883  -0.5898709  -0.36369030
[36,] -14.2113823 -16.6100486   9.07203345 -13.4515467  -2.0797826  -3.1567749   2.94481184
[37,] -10.3241338 -21.8739290  -0.25448952  -4.2178114  -5.8253442  -2.2815638   2.57099401
[38,]  -1.6878990 -13.9744770 -32.25639847   1.7264204  -6.8524217  11.0633408   4.89836794
[39,] -21.9957957 -24.0405721  22.38147318  12.4602238   0.9192234   7.6823693   0.90812105
[40,] -27.3899348 -15.4321304  13.48446066   5.0113346  -2.4836177  -4.2459026   6.84884606
[41,] -36.8582514 -10.8359097   4.53814047  -4.9203118  12.2050066  -4.2598492  -1.97133591
[42,] -29.1632178  -5.8974902  17.50675815 -13.0108622  -1.3726696   7.3525642  -1.22636356
[43,] -39.0671787  22.1658349  -3.46728792  -2.2345130   5.9431736  -8.7253538  -0.08618077
[44,] -13.5103452 -28.6644930  -6.58252140 -11.1545147   2.1688582  -4.5438992   0.97442827
[45,] -52.4375907  51.4437648 -10.05342584  -9.6192156   1.9129401   5.2524403   9.21448312
[46,] -31.0312852 -12.0406147 -21.53204798  15.8935480  14.8361158  -4.9785873   2.95657858
[47,] -73.7162166   4.2544914  -3.95079643 -10.2388023  -6.6166558   7.3302988 -12.68745922

　　

 绘制各个科目主成分碎石图

screeplot(PCA,type="lines")