.
Use K-means to cluster the data in Exercise 5, k = 2, first
including all data and then including all OTUs except for D.
a. Does the cluster membership of C change when D is excluded?
b. Try to force OTU C into a cluster with D, E, and F by setting the initial
cluster centers at the coordinates of A and D.
.
To test the effects of different measures of intercluster distance,
perform hierarchical clustering on the following OTUs:
x y
A 1.0 1.5
B 1.0 1.0
C 3.0 1.0
D 5.5 1.0
E 7.0 1.0
F 7.0 2.0
G 7.0 5.0
H 6.0 6.0
I 8.0 6.0
a. First perform hierarchical clustering using single-linkage clustering. How
many clusters having three closely related members are there? Which two
clusters are more closely related?
b. Repeat the hierarchical clustering, except this time use complete linkage
clustering. How many three-member clusters are there?Which two of these
three-member clusters are more closely related?
c. Plot the data points, and explain the reasons why a and b above gave
different results. Also, explain with a diagram why the G, H, I clusters
differ for single-linkage and complete-linkage clustering.