Decision Trees
Decision tree is a classifier in the form of a tree structure. Each node is either
- A leaf node - indicates the value of the target attribute (class)
- A decision node - specifies some test to be carried out usually on a single attribute value with one branch for each outcome of the rest.
Decision Tree Example :

Each internal node tests an attribute
Each leaf node assigns a classification
Each branch corresponds To an attribute value
Decision Tree Defn :
A decision tree is a tree in which -
Decision tree for classificationDecision tree is a classifier in the form of a tree structure. Each node is either
- A leaf node - indicates the value of the target attribute (class)
- A decision node - specifies some test to be carried out usually on a single attribute value with one branch for each outcome of the rest.
Decision Tree Example :
Each internal node tests an attribute
Each leaf node assigns a classification
Each branch corresponds To an attribute value
Decision Tree Defn :
A decision tree is a tree in which -
- Each non-leaf node has associated with it an attribute (feature)
- Each leaf node has associated with it a classification (+ or -)
- Each arc corresponds to one possible value of the attribute of its parent node.
A decision tree used to classify an example.
- Start from the root node.
- Follow the appropriate decision branches
- On reaching a leaf node the predicted class is obtained
Classification us9ing Decision tree
What type of functions can decision trees represent ?
Disjunction of conjunctions
Try representing the following functions:
What type of functions can decision trees represent ?
Disjunction of conjunctions
Try representing the following functions:
- AND
- OR
- XOR
- majority
Decision tree induction
- Top down greedy search through the space of decision trees.
- Use training data
- Quinlan developed ID3 in 1973 based on the CLS algorithm.
Top-Down Induction of Decision Trees : ID3
- A ← the "best" decision attribute for next node
- Assign A as decision attribute for node
- For each value of A create new descendant
- Sort training examples to leaf node according to attribute value of the branch
- If all training example are perfectly classified (same value of target attribute) stop, else iterate over new leaf nodes.
1. Input :
- Atts - A set of non-target attributes
- Q - target attribute
- S - training set
2. Returns a decision tree
If S is empty, return a single node with value Failure
If S consists of records of the same class, return a single leaf node with that value.
If Atts is empty, then return a single node with the value of the most frequent value of Q in S.
Begin
End
Thanks for the information! Kudos!
ReplyDeleteThis is the genuin e business request supporting the development of machine information investigation. Data Analytics Courses
ReplyDeletei must say and thanks for the information.
ReplyDeleteData Science Certification in Bangalore
Very impressive and interesting blog found to be well written in a simple manner that everyone will understand and gain the enough knowledge from your blog being more informative is an added advantage for the users who are going through it. Once again nice blog keep it up.
ReplyDelete360DigiTMG Artificial Intelligence Course
Attend The Data Science Courses From ExcelR. Practical Data Science Courses Sessions With Assured Placement Support From Experienced Faculty. ExcelR Offers The Data Science Courses.
ReplyDeleteData Science Courses
Thank you for sharing the article. The data that you provided in the blog is informative and effective.
ReplyDeleteTableau Training in Hyderabad
I am really happy to say it’s an interesting post to read . I learn new information from your article , you are doing a great job . Keep it up
ReplyDeleteDevops Training in Hyderabad
Hadoop Training in Hyderabad
Python Training in Hyderabad
Tableau Training in Hyderabad
Selenium Training in Hyderabad
Today the wood is creatively significant for making furniture or model on account of its occasionally dull tones and delightful twisted examples. Stump Removal Elk Grove
ReplyDeleteI am really happy to say it’s an interesting post to read . I learn new information from your article , you are doing a great job . Keep it up
ReplyDeleteDevops Training in Hyderabad
Hadoop Training in Hyderabad
Python Training in Hyderabad
Tableau Training in Hyderabad
Selenium Training in Hyderabad
Selenium Training in Hyderabad