Chapter 7
Decisions, Decisions, Decisions
IN THIS CHAPTER
Finding out about decision trees
Creating a decision tree for the iris dataset
Working with a decision tree for the Acute inflammations dataset from UCI
A decision tree is a graphical way of representing knowledge. As its name implies, it's a tree-like structure that shows decisions about something, and it’s useful in many fields, from management to medicine.
Think of a decision tree as a way to structure a sequence of questions and possible answers. One prominent use of a decision tree is to show the flow of decision-making to a nontechnical audience.
Decision Tree Components
Figure 7-1 shows a decision tree for classifying irises along with decision tree terminology. You might recall from Chapter 6 that the iris dataset (downloaded from the UCI Machine Learning (ML) Repository and designated as iris.uci) consists of 150 rows and 5 columns. The 150 rows represent individual flowers, with 50 each of the setosa, versicolor, and virginica species. The five columns are sepal.length, sepal.width, petal.length, petal.width, and species.
FIGURE 7-1: A decision tree for classifying irises.
The decision tree is really an upside ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access