1. For ITCS 6265/8265 Fall 2009 TA: Fei Xu UNC Charlotte

2. Contents What is weka? RAFF data format Interface Explorer … Trouble shooting

3. WEKA: the bird Copyright: Martin Kramer (mkramer@wxs.nl)

4. Weka: Data Mining Software Weka is a collection of machine learning algorithms for data mining tasks. The algorithms can either be applied directly to a dataset or called from your own Java code. Weka contains tools for data pre-processing, classification, regression, clustering, association rules, and visualization. Weka is open source software in JAVA issued under the GNU General Public License. http://www.cs.waikato.ac.nz/ml/weka/

5. WEKA only deals with “flat” files Weka has it own file format: Attribute-Relation File Format (ARFF) Header section and Data section Supported attributes: numeric, nominal, string, date Details at: http://www.cs.waikato.ac.nz/~ml/weka/arff.html

6. Example @RELATION auto-mpg @ATTRIBUTE mpg REAL @ATTRIBUTE cylinders REAL @ATTRIBUTE displacement REAL @ATTRIBUTE horsepower REAL @ATTRIBUTE weight REAL @ATTRIBUTE acceleration REAL @ATTRIBUTE year REAL @ATTRIBUTE origin {1,2,3} % 1 = usa; 2 = europe; 3 = japan @DATA 15.0 8 350.0 165.0 3693. 11.5 70 1 18.0 8 318.0 150.0 3436. 11.0 70 1 17.0 8 302.0 140.0 3449. 10.5 70 1 15.0 8 429.0 198.0 4341. 10.0 70 1 14.0 8 440.0 215.0 4312. 8.5 70 1

7. Explorer Interface Explorer pre-processing the data building “classifiers” (demo) clustering data finding associations attribute selection data visualization

9. Other interface More at: http://www.cs.waikato.ac.nz/ml/weka/index_documentation.htmlhttp://www.cs.waikato.ac.nz/ml/weka/index_documentation.html Experimenter makes it easy to compare the performance of different learning schemes Java-Beans-based interface for setting up and running machine learning experiments. Command line interface

10. Trouble shooting OutOfMemoryException Find “RunWeka.ini” under weka installation directory, default location in windows is “C:\Program Files\Weka- 3-6”. Find “maxheap” and change the value to proper size, for example 512M More at: http://weka.wikispaces.com/Troubleshootinghttp://weka.wikispaces.com/Troubleshooting