(a) (b)

Next step of using the K-means for the toy data set. (a) The two centres have

ed. (b) New membership functions assigned to data points.

these new updates, two cluster centres stopped change. A

process was thus terminated.

The membership function values in two steps of using the K-means algorithm

et of seven data points and two clusters shown in Figure 2.22.

Step 1

Step 2

x

݂௜ሺۯሻ

݂௜ሺ۰ሻ

x

݂௜ሺۯሻ

݂௜ሺ۰ሻ

1

1

0

1

1

0

2

1

0

2

1

0

3

0

1

3

1

0

4

0

1

4

0

1

5

0

1

5

0

1

6

0

1

6

0

1

7

0

1

7

0

1

R function for the K-means algorithm is kmeans and its syntax is

elow, where x is a matrix and centers is the parameter for

g the number of clusters,

kmeans(x,centers,···)

e 2.24 shows the application of a data set of two clusters. A K-

odel was constructed on this data set and it indeed revealed this

ructure. Suppose the data set was saved in a variable named by x.

below was used to apply the kmeans function to the data set,

model=kmeans(x,centers=2)