""" Jython-WEKA data mining example Author: Pradeep Kishore Gowda This Program demonstrates the use of Simple Classification Algorithm (Using j48 decision Tree) on Iris Data set """ import java.io.FileReader as FR import weka.core.Instances as Instances import weka.classifiers.trees.J48 as J48 # Load Data File file = FR('iris.arff') data = Instances(file) """ The sample data reads like this @relation iris @attribute sepallength numeric @attribute sepalwidth numeric @attribute petallength numeric @attribute petalwidth numeric @attribute class {Iris-setosa,Iris-versicolor,Iris-virginica} @data 5.1,3.5,1.4,0.2,Iris-setosa """ #set the class Index - the index of the dependent variable data.setClassIndex(4) #create the model j48 = J48() j48.buildClassifier(data) #print out the built model print j48 # you do not have to call the j48.toString(), # My guess is Python's default __str__ method calls #.toString Internally. ? # let us classify an instance and verify the result myinstance = data.instance(0) klass = j48.classifyInstance(myinstance) #0.0 #what does 0.0 mean? print data.attribute(data.classIndex()).value(klass) #'Iris-setosa'
Update: This thread on wekalist gives a similar example.
URL: http://pradeepgowda.com/programming/weka-j48-classifier-example-using-jython/
© 2010 Pradeep Gowda