combMat: Combining Matrix In RmixmodCombi: Combining Mixture Components for Clustering

Description

Create a combining matrix

Usage

 `1` ```combMat(K,l1,l2) ```

Arguments

 `K` The original number of classes: the matrix will define a combining from K to (K-1) classes. `l1` Label of one of the two classes to be combined. `l2` Label of the other class to be combined.

Value

If `z` is a vector (length K) whose kth entry is the probability that an observation belongs to the kth class in a K-class classification, then `combiM %*% z` is the vector (length K-1) whose kth entry is the probability that the observation belongs to the kth class in the K-1-class classification obtained by combining classes `l1` and `l2` in the initial classification.

J.-P. Baudry

References

J.-P. Baudry, A. E. Raftery, G. Celeux, K. Lo and R. Gottardo (2010). Combining mixture components for clustering. Journal of Computational and Graphical Statistics, 19(2):332-353.

`mixmodCombi`
 ``` 1 2 3 4 5 6 7 8 9 10 11``` ```set.seed(1) data(Baudry_etal_2010_JCGS_examples) res <- mixmodCombi(ex4.1, nbCluster = 1:8) res@hierarchy[[5]]@proba # each line of this matrix is the vector of the posterior probabilities of # each class for an observation in the 5-cluster solution t(combMat(5, 3, 4) %*% t(res@hierarchy[[5]]@proba) ) # each line of this matrix is the vector of # the posterior probabilities of each class for an observation in the 4-cluster solution obtained by # combining clusters 3 and 4 in the 5-cluster solution ```