Learning Decision Trees Brief tutorial by M Werner.

Slides:



Advertisements
Similar presentations
C4.5 algorithm Let the classes be denoted {C1, C2,…, Ck}. There are three possibilities for the content of the set of training samples T in the given node.
Advertisements

IT 433 Data Warehousing and Data Mining
Hunt’s Algorithm CIT365: Data Mining & Data Warehousing Bajuna Salehe
Introduction Training Complexity, Pruning CART vs. ID3 vs. C4.5
Data Mining Classification: Basic Concepts, Decision Trees, and Model Evaluation Lecture Notes for Chapter 4 Part I Introduction to Data Mining by Tan,
Non-Metric Methods: Decision Trees Alexandros Potamianos Dept of ECE, Tech. Univ. of Crete Fall
Bab /44 Bab 4 Classification: Basic Concepts, Decision Trees & Model Evaluation Part 1 Classification With Decision tree.
1 Data Mining Classification Techniques: Decision Trees (BUSINESS INTELLIGENCE) Slides prepared by Elizabeth Anglo, DISCS ADMU.
Decision Tree.
Chapter 21 Statistical Decision Theory
Chapter 7 – Classification and Regression Trees
Chapter 7 – Classification and Regression Trees
Decision Tree under MapReduce Week 14 Part II. Decision Tree.
Decision Trees.
Decision Trees Instructor: Qiang Yang Hong Kong University of Science and Technology Thanks: Eibe Frank and Jiawei Han.
Decision Tree Rong Jin. Determine Milage Per Gallon.
ID3 Algorithm Abbas Rizvi CS157 B Spring What is the ID3 algorithm? ID3 stands for Iterative Dichotomiser 3 Algorithm used to generate a decision.
About ISoft … What is Decision Tree? Alice Process … Conclusions Outline.
© Vipin Kumar CSci 8980 Fall CSci 8980: Data Mining (Fall 2002) Vipin Kumar Army High Performance Computing Research Center Department of Computer.
Data Mining with Decision Trees Lutz Hamel Dept. of Computer Science and Statistics University of Rhode Island.
Darlene Goldstein 29 January 2003 Receiver Operating Characteristic Methodology.
Decision Trees an Introduction.
Decision Trees (2). Numerical attributes Tests in nodes are of the form f i > constant.
C82MCP Diploma Statistics School of Psychology University of Nottingham 1 Overview of Lecture Independent and Dependent Variables Between and Within Designs.
The joy of Entropy.
The joy of Entropy. Administrivia Reminder: HW 1 due next week No other news. No noose is good noose...
R OBERTO B ATTITI, M AURO B RUNATO. The LION Way: Machine Learning plus Intelligent Optimization. LIONlab, University of Trento, Italy, Feb 2014.
Multivariate Data and Matrix Algebra Review BMTRY 726 Spring 2012.
Introduction to Directed Data Mining: Decision Trees
Tests of significance & hypothesis testing Dr. Omar Al Jadaan Assistant Professor – Computer Science & Mathematics.
Data Mining: Classification
Midterm Review Rao Vemuri 16 Oct Posing a Machine Learning Problem Experience Table – Each row is an instance – Each column is an attribute/feature.
1 Data Mining Lecture 3: Decision Trees. 2 Classification: Definition l Given a collection of records (training set ) –Each record contains a set of attributes,
Decision Trees & the Iterative Dichotomiser 3 (ID3) Algorithm David Ramos CS 157B, Section 1 May 4, 2006.
Chapter 9 – Classification and Regression Trees
Decision Tree Learning Debapriyo Majumdar Data Mining – Fall 2014 Indian Statistical Institute Kolkata August 25, 2014.
Classification and Prediction Compiled By: Umair Yaqub Lecturer Govt. Murray College Sialkot Readings: Chapter 6 – Han and Kamber.
Data Mining Application: CART. CART: Binary Recursion Decision Tree program from Salford Systeems 30-day evaluation copy from.
Chapter 6 Classification and Prediction Dr. Bernard Chen Ph.D. University of Central Arkansas.
Exercises Decision Trees In decision tree learning, the information gain criterion helps us select the best attribute to split the data at every node.
Classification (slides adapted from Rob Schapire) Eran Segal Weizmann Institute.
Decision Trees Example of a Decision Tree categorical continuous class Refund MarSt TaxInc YES NO YesNo Married Single, Divorced < 80K> 80K Splitting.
ECE 471/571 – Lecture 20 Decision Tree 11/19/15. 2 Nominal Data Descriptions that are discrete and without any natural notion of similarity or even ordering.
Classification Today: Basic Problem Decision Trees.
COMP53311 Classification Prepared by Raymond Wong The examples used in Decision Tree are borrowed from LW Chan ’ s notes Presented by Raymond Wong
Big Data Analysis and Mining Qinpei Zhao 赵钦佩 2015 Fall Decision Tree.
1 Classification: predicts categorical class labels (discrete or nominal) classifies data (constructs a model) based on the training set and the values.
Classification and Regression Trees
Combining multiple learners Usman Roshan. Decision tree From Alpaydin, 2010.
Machine Learning Recitation 8 Oct 21, 2009 Oznur Tastan.
Decision Tree. Classification Databases are rich with hidden information that can be used for making intelligent decisions. Classification is a form of.
1 By: Ashmi Banerjee (125186) Suman Datta ( ) CSE- 3rd year.
By N.Gopinath AP/CSE.  A decision tree is a flowchart-like tree structure, where each internal node (nonleaf node) denotes a test on an attribute, each.
DECISION TREES An internal node represents a test on an attribute.
Decision Trees an introduction.
Decision Trees.
Trees, bagging, boosting, and stacking
Ch9: Decision Trees 9.1 Introduction A decision tree:
Classification and Prediction
Evaluate the expression ( i) + ( i) and write the result in the form a + bi. Choose the answer from the following: i i i.
Roberto Battiti, Mauro Brunato
Figure 3 Transcriptome studies performed in the target
Data Mining – Chapter 3 Classification

Evaluate the limit: {image} Choose the correct answer from the following:
Junheng, Shengming, Yunsheng 10/19/2018
Decision Tree  Decision tree is a popular classifier.
Decision Tree  Decision tree is a popular classifier.
Data Mining CSCI 307, Spring 2019 Lecture 15
Presentation transcript:

Learning Decision Trees Brief tutorial by M Werner

Medical Diagnosis Example Goal – Diagnose a disease from a blood test Clinical Use –Blood sample is obtained from a patient –Blood is tested to measure current expression of various proteins, say by using a DNA microarray –Data is analyzed to produce a Yes or No answer

Data Analysis Use a decision tree such as: P1 > K1 P2 > K2 P3 > K3P4 > K4 YesNoYes No Yes Y N YY Y Y N N N N No Y

How to Build the Decision Tree Start with samples of blood from patients known to either have the disease or not (training set). Suppose there are 20 patients and 10 are known to have the disease and 10 not From the training set get expression levels for all proteins of interest i.e. if there are 20 patients and 50 proteins we get a 50 X 20 array of real numbers Rows are proteins Columns are patients

Choosing the decision nodes We would like the tree to be as short as possible Start with all 20 patients in one group Choose a protein and a level that gains the most information Px > Kx 10/10 9/31/7 10 have disease 10 don’t Possible splitting condition Mostly diseased Mostly not diseased Py > Ky 10/10 7/73/3 Alternative splitting condition

How to determine information gain Purity – A measure to which the patients in a group share the same outcome. A group that splits 1/7 is fairly pure – Most patients don’t have the disease 0/8 is even purer 4/4 is the opposite of pure. This group is said to have high entropy. Knowing that a patient is in this group does not make her more or less likely to have the disease. The decision tree should reduce entropy as test conditions are evaluated

Measuring Purity (Entropy) Let f(i,j)=Prob(Outcome=j in node i) i.e. If node 2 has a 9/3 split –f(2,0) = 9/12 =.75 –f(2,1) = 3/12 =.25 Gini impurity: Entropy:

Computing Entropy

Goal is to use a test which best reduces total entropy in the subgroups

Building the Tree

Links publications/courses/ece_8463/lectures/cu rrent/lecture_27/lecture_27.pdfhttp:// publications/courses/ece_8463/lectures/cu rrent/lecture_27/lecture_27.pdf Decision Trees & Data Mining Andrew Moore Tutorial