An Introduction to WEKA

An Introduction to WEKA Contributed by Yizhou Sun 2008

Contributed by Yizhou Sun 2008 An Introduction to WEKA

Content What iS WEKA? e EXPLorer e Preprocess data ● Classification Clustering Association rules Attribute Selection Data visualization References and resources

Content  What is WEKA?  The Explorer:  Preprocess data  Classification  Clustering  Association Rules  Attribute Selection  Data Visualization  References and Resources 2 1/29/2021

What is WEKA? o Waikato Environment for Knowledge analysis It's a data mining/ machine learning tool developed by Department of computer Science, university of waikato, New Zealand e Weka is also a bird found only on the islands of new zealand

What is WEKA?  Waikato Environment for Knowledge Analysis  It’s a data mining/machine learning tool developed by Department of Computer Science, University of Waikato, New Zealand.  Weka is also a bird found only on the islands of New Zealand. 3 1/29/2021

Download and Install WeKa Website http://www.cs.waikatoac.nz/ml/weka/index.htm Support multiple platforms(written in java) Windows Mac os X and linux

Download and Install WEKA  Website: http://www.cs.waikato.ac.nz/~ml/weka/index.html  Support multiple platforms (written in java):  Windows, Mac OS X and Linux 4 1/29/2021

Main Features e 49 data preprocessing tools o 76 classification /regression algorithms 8 clustering algorithms 3 algorithms for finding association rules e 15 attribute/ subset evaluators+ 10 search algorithms for feature selection

Main Features  49 data preprocessing tools  76 classification/regression algorithms  8 clustering algorithms  3 algorithms for finding association rules  15 attribute/subset evaluators + 10 search algorithms for feature selection 5 1/29/2021

Main gu Three graphical user interfaces eka ●“ The explorer”( exploratory data analysis) Waikato Environment for The Experimenter"(experimental Version 3. 4. 12 environment) (c)1999·200 niversity of Waikato ●“ The Knowledge Flow( new process model inspired interface Experimenter KnowledgeFlow

Main GUI  Three graphical user interfaces  “The Explorer” (exploratory data analysis)  “The Experimenter” (experimental environment)  “The KnowledgeFlow” (new process model inspired interface) 6 1/29/2021

Content What iS WEKa? The explorer e Preprocess data ● Classification Clustering Association rules Attribute Selection Data visualization References and resources

Content  What is WEKA?  The Explorer:  Preprocess data  Classification  Clustering  Association Rules  Attribute Selection  Data Visualization  References and Resources 7 1/29/2021

EXplorer: pre-processing the data Data can be imported from a file in various formats: ARFF CSV, C4.5,binary e Data can also be read from a url or from an SQl database (using jDBC ●Pre- processing tools in WEKa are called“ filters” WEKA contains filters for Discretization, normalization, resampling, attribute selection transforming and combining attributes

8 1/29/2021 Explorer: pre-processing the data  Data can be imported from a file in various formats: ARFF, CSV, C4.5, binary  Data can also be read from a URL or from an SQL database (using JDBC)  Pre-processing tools in WEKA are called “filters”  WEKA contains filters for:  Discretization, normalization, resampling, attribute selection, transforming and combining attributes, …

WEKA only deals with"flatfiles arelation heart-disease-simplified (attribute age numeric @attribute sexi female, male) @attribute chest-pain_type typ_angina, asympt, non_anginal, atyp_anginal (attribute cholesterol numeric @attribute exercise_induced _angina no, yes @attribute class present, not_present) (ad 63, male, typ_angina, 233, no, not_present 67, male, asympt. 286. ves, present 67, male, asympt, 229, yes, present Flat file in 38, female, non_anginal, no, not_present ARFF format 1/29/2021

9 1/29/2021 @relation heart-disease-simplified @attribute age numeric @attribute sex { female, male} @attribute chest_pain_type { typ_angina, asympt, non_anginal, atyp_angina} @attribute cholesterol numeric @attribute exercise_induced_angina { no, yes} @attribute class { present, not_present} @data 63,male,typ_angina,233,no,not_present 67,male,asympt,286,yes,present 67,male,asympt,229,yes,present 38,female,non_anginal,?,no,not_present ... WEKA only deals with “flat” files

WEKA only deals with"flatfiles arelation heart-disease-simplified numeric attribute (attribute age numeric @attribute sexi female, male) -nominal attribute @attribute chest-pain_type typ_angina, asympt, non_anginal, atyp_anginal (attribute cholesterol numeric @attribute exercise_induced _angina no, yes @attribute class present, not_present) (ad 63, male, typ_angina, 233, no, not_present 67, male, asympt. 286. ves, present 67, male, asympt, 229, yes, present 38, female, non_anginal, no, not_present

10 1/29/2021 @relation heart-disease-simplified @attribute age numeric @attribute sex { female, male} @attribute chest_pain_type { typ_angina, asympt, non_anginal, atyp_angina} @attribute cholesterol numeric @attribute exercise_induced_angina { no, yes} @attribute class { present, not_present} @data 63,male,typ_angina,233,no,not_present 67,male,asympt,286,yes,present 67,male,asympt,229,yes,present 38,female,non_anginal,?,no,not_present ... WEKA only deals with “flat” files