Decision Tree Example

    Example of Decision Tree

Let’s understand decision trees with the help of an example:

 

Day	Weather	Temperature	Humidity	Wind	Play Tennis
D1	Sunny	Hot	High	Weak	No
D2	Sunny	Hot	High	Strong	No
D3	Overcast	Hot	High	Weak	Yes
D4	Rain	Mild	High	Weak	Yes
D5	Rain	Cool	Normal	Weak	Yes
D6	Rain	Cool	Normal	Strong	No
D7	Overcast	Cool	Normal	Strong	Yes
D8	Sunny	Mild	High	Weak	No
D9	Sunny	Cool	Normal	Weak	Yes
D10	Rain	Mild	Normal	Weak	Yes
D11	Sunny	Mild	Normal	Strong	Yes
D12	Overcast	Mild	High	Strong	Yes
D13	Overcast	Hot	Normal	Weak	Yes
D14	Rain	Mild	High	Strong	No

 The above dataset has 9 Yes and 5 No Entries.

We need to find the Information Gain for all the attributes.

Lets first find the Information Gain for the attribute  Outlook

Values (outlook)= Sunny, Overcast, Rain

Lets first find the Information Gain for the attribute Temerature.

Values (Temp) = Hot, Mild, Cool

Attribute: Humidity

Values (Humidity)= High, Normal

Attribute: Wind

Values (Wind)= Weak, Strong