Databases Reference
In-Depth Information
have been shown to each user (the number of impressions) and how
many times each has clicked on an ad (number of clicks).
Figure 3-9
shows a simplistic picture that illustrates what this might
look like.
Figure 3-9. Clustering in two dimensions; look at the panels in the left
column from top to bottom, and then the right column from top to
bottom
Visually you can see in the top-left that the data naturally falls into
clusters. This may be easy for you to do with your eyes when it's only
in two dimensions and there aren't that many points, but when you
get to higher dimensions and more data, you need an algorithm to
help with this pattern-finding process. k-means algorithm looks for
clusters in
d
dimensions, where
d
is the number of features for each
data point.
