CODEWITHSUNDEEP
rmachine-learningcluster-analysis
user24318
user24318

Reputation: 485

assign cluster labels to data using a cluster assignment matrix

Hi I am using R and have a cluster assignment matrix that comes out of my clustering function. (I am applying a clustering algorithm on a gaussian mixture data) I want to create a data matrix of clusters. Here is a toy example of what I want to do. 

#simulate data

dat=Z<-c(rnorm(2,0,1),rnorm(2,2,3),rnorm(3,0,1),rnorm(3,2,3))
 dat
 [1] -0.5350681  1.0444655  2.9229136  8.2528266 -0.7561170 -1.0240702     -1.0012780
 [8] -0.1322981  7.8525855  2.2278264

# Making up a cluster assignment matrix (actually this one comes out of my      
#clustering function

amat<-matrix(c(1,1,0,0,1,1,1,0,0,0,0,0,1,1,0,0,0,1,1,1), ncol=2, nrow=10)
        amat
       [,1] [,2]
 [1,]    1    0
 [2,]    1    0
 [3,]    0    1
 [4,]    0    1
 [5,]    1    0
 [6,]    1    0
 [7,]    1    0
 [8,]    0    1
 [9,]    0    1
[10,]    0    1

I want to create dataframe or vector called (say) "clust" that contains cluster labels as follows using the assignment matrix given above.Basically it uses first column and second column of assignment matrix and assigns label 1 to data coming from normal distribution N(0,1) and assigns label 2 to the data coming from normal distribution N(2,3).Any help is appreciated. Thanks in advance.

    # clust should look like this (I have no idea how to create this using amat and dat)

    clust
 [1] 1 1 2 2 1 1 1 2 2 2

Upvotes: 0

Views: 975

Answers (2)

Has QUIT--Anony-Mousse
Has QUIT--Anony-Mousse

Reputation: 77485

Isn't this essentially

1 * column1 + 2 * column2 +3 * column3 and so on?

that should be straight forward to write as a matrix multiplocation woth [1,2,3,4,...] and a sum operation.

Upvotes: 1

Pierre L
Pierre L

Reputation: 28461

The vector is already binary. We can add 1L to the second column:

clust <- amat[,2] + 1L
[1] 1 1 2 2 1 1 1 2 2 2

(The suffix L coerces the value to integer)

Upvotes: 1

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