Cluster Analysis Flashcards
1
Q
Define a dissimilarity matrix
A
dij = dji
dij ≥ 0
dii = 0
2
Q
Give the squared euclidean distance
A
dij^2 = sum(k=1 to p) (xik - xjk)^2
3
Q
Define a similarity matrix
A
sij = sji
sij ≤ sii
4
Q
How do you transform between a dissimilarity matrix and a similarity matrix?
A
dij = (sii + sjj - 2sij)^(1/2)
5
Q
When is a group homogenous?
A
Members are close to each other, and distant from other groups
6
Q
How do you perform single linkage cluster analysis?
A
- choose smallest distance between any two points
- form this cluster
- select minimum distance from this cluster to all other points
7
Q
How do you perform complete linkage cluster analysis?
A
- choose smallest distance between any two points
- form this cluster
- select maximum distance from this cluster to all other points
