r - 麦克鲁斯特 : Order of input parameters affecting clustering results

Question

我正在使用mclust使用不同数量的输入(下面脚本中的 X、Y、Z、R 和 S)查看数据集中的各种聚类:

例如

elements<-cbind(X,Y,Z,R,S)
dataclust<-Mclust(elements)

我刚刚发现输入参数的顺序很重要并且会影响结果；换句话说elements <- cbind(X,Y,Z,R,S)给出了与 elements-<cbind(Y,Z,X,R,S) 不同的簇。我的理解是所有输入参数在聚类分析中具有相同的权重和重要性。是我错了还是bug？

我在 R 2.15.3 和其他 2 个 R 版本中看到了这一点。

对上述内容的任何评论或解释都值得赞赏。

Answer 1

不幸的是，我无法评论或编辑我之前的评论，所以我发布了一个答案。 @m-dz 让我走上了一条我认为已经揭示了可能答案的道路。具体来说:

> library(mclust)
    __  ___________    __  _____________
   /  |/  / ____/ /   / / / / ___/_  __/
  / /|_/ / /   / /   / / / /\__ \ / /   
 / /  / / /___/ /___/ /_/ /___/ // /    
/_/  /_/\____/_____/\____//____//_/    version 5.2.2
Type 'citation("mclust")' for citing this R package in publications.

> testDataA <- read.table("http://fimi.ua.ac.be/data/chess.dat")

> summary(Mclust(subset(testDataA, select = c(V1, V3, V5, V7, V9, V11))))
----------------------------------------------------
Gaussian finite mixture model fitted by EM algorithm 
----------------------------------------------------

Mclust EII (spherical, equal volume) model with 9 components:

 log.likelihood    n df      BIC       ICL
      -3597.466 3196 63 -7703.32 -7735.137

Clustering table:
  1   2   3   4   5   6   7   8   9 
774 150 752 486 227 224 238 178 167 

> summary(Mclust(subset(testDataA, select = c(V11, V9, V1, V3, V5, V7))))
----------------------------------------------------
Gaussian finite mixture model fitted by EM algorithm 
----------------------------------------------------

Mclust EII (spherical, equal volume) model with 9 components:

 log.likelihood    n df      BIC       ICL
      -3597.466 3196 63 -7703.32 -7735.137

Clustering table:
  1   2   3   4   5   6   7   8   9 
774 150 752 486 227 224 238 178 167 

> sessionInfo()
R version 3.3.2 (2016-10-31)
Platform: x86_64-apple-darwin13.4.0 (64-bit)
Running under: macOS Sierra 10.12.5

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] mclust_5.2.2

loaded via a namespace (and not attached):
[1] tools_3.3.2

如您所见，这会产生两个与 @m-dz 匹配的解决方案!然而，我之前所做的是加载 psych 包。我现在看到这是从 mclust 屏蔽 sim。我猜这会导致错误的解决方案:

> library(psych)

Attaching package: ‘psych’

The following object is masked from ‘package:mclust’:

    sim

> testDataB <- read.file(f = "http://fimi.ua.ac.be/data/chess.dat")
Data from the .data file http://fimi.ua.ac.be/data/chess.dat has been loaded.

> summary(Mclust(subset(testDataB, select = c(X1, X3, X5, X7, X9, X11))))
----------------------------------------------------
Gaussian finite mixture model fitted by EM algorithm 
----------------------------------------------------

Mclust EEV (ellipsoidal, equal volume and shape) model with 2 components:

 log.likelihood    n df      BIC      ICL
       3547.068 3195 49 6698.738 6692.126

Clustering table:
   1    2 
2759  436 

> summary(Mclust(subset(testDataB, select = c(X11, X9, X1, X3, X5, X7))))
----------------------------------------------------
Gaussian finite mixture model fitted by EM algorithm 
----------------------------------------------------

Mclust EEV (ellipsoidal, equal volume and shape) model with 6 components:

 log.likelihood    n  df      BIC      ICL
       18473.94 3195 137 35842.37 35834.51

Clustering table:
  1   2   3   4   5   6 
431 932 210 881 524 217 

> sessionInfo()
R version 3.3.2 (2016-10-31)
Platform: x86_64-apple-darwin13.4.0 (64-bit)
Running under: macOS Sierra 10.12.5

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] psych_1.6.9  mclust_5.2.2

loaded via a namespace (and not attached):
[1] parallel_3.3.2 tools_3.3.2    foreign_0.8-67 mnormt_1.5-5