[R] simulating Gaussian Mixture Method

[Peng Jiang]

  Hi,

  I have a mixture pdf which has three components, each satisfies the  
6 dimension normal distribution.

   I use mvrnorm() from the MASS library to generate 1000 samples for  
each component  and I add them
  to get the random samples which satisfies with the mixture  
distribution.

  I use Mclust() from the mclust library to get the model of the  
samples and strange things happened.
  First it gave a warning

 > samplesMclust <- Mclust( samples )

  Warning messages:
1: In summary.mclustBIC(Bic, data, G = G, modelNames = modelNames) :
   best model occurs at the min or max # of components considered
2: In Mclust(samples) : optimal number of clusters occurs at min choice

Then I input
 > samplesMclust

  best model: XXI with 1 components

  it says the best model is with 1 component !

   I am confused ... Is it because the way that I generate samples is  
wrong???

   thanks so much !




--------------------------
Peng Jiang
江鹏
Ph.D. Candidate

Antai College of Economics & Management
安泰经济管理学院
Department of Mathematics
数学系
Shanghai Jiaotong University (Minhang Campus)
800 Dongchuan Road
200240 Shanghai
P. R. China