Classifying Single Instance in Weka (MultilayerPerceptron)

I trained and created a MultilayerPerceptron model using weka.jar version 3.6.10 . I saved the model file to my computer and now I would like to use it to classify a single instance in my Java code. I would like to get a prediction for the attribute "class". i found answer here And I changed the values to what I needed. What I do is the following:

import weka.classifiers.Classifier;  import weka.classifiers.functions.MultilayerPerceptron;  import weka.core.Attribute;  import weka.core.FastVector;  import weka.core.Instance;  import weka.core.Instances;  import weka.core.SparseInstance;  import weka.core.SerializationHelper;  public class JavaApplication {        public static void main(String[] args) {          JavaApplication q = new JavaApplication();          double result = q.classify(-1.18,12.76,1.7297841);          System.out.println(result);      }        private Instance inst_co;        public double classify(double x, double y, double z)  {            // Create attributes to be used with classifiers          // Test the model          double result = -1;          try {                FastVector attributeList = new FastVector();                Attribute x_acc= new Attribute("x_acc");              Attribute y_acc= new Attribute("y_acc");              Attribute z_acc= new Attribute("z_acc");                FastVector classVal = new FastVector();              classVal.addElement("Walking");              classVal.addElement("Jogging");              classVal.addElement("Downstairs");              classVal.addElement("Sitting");              classVal.addElement("Upstairs");                  attributeList.addElement(x_acc);              attributeList.addElement(y_acc);              attributeList.addElement(z_acc);              attributeList.addElement(new Attribute("@@class@@",classVal));                Instances data = new Instances("TestInstances",attributeList,0);                  // Create instances for each pollutant with attribute values latitude,              // longitude and pollutant itself              inst_co = new SparseInstance(data.numAttributes());              data.add(inst_co);                // Set instance's values for the attributes "latitude", "longitude", and              // "pollutant concentration"              inst_co.setValue(x_acc, x);              inst_co.setValue(y_acc, y);              inst_co.setValue(z_acc, z);              // inst_co.setMissing(cluster);                              // load classifier from file             Classifier cls_co = (MultilayerPerceptron) SerializationHelper                     .read("/Users/ALL-TECH/Desktop/Sensors application/FewDataGenerated/model.model");                result = cls_co.classifyInstance(inst_co);          } catch (Exception e) {              // TODO Auto-generated catch block              e.printStackTrace();          }          return result;      }  }  

and my arff file looks like this :

@RELATION fewOfDataCsv    @ATTRIBUTE x_acc  NUMERIC  @ATTRIBUTE y_acc  NUMERIC  @ATTRIBUTE z_acc  NUMERIC  @ATTRIBUTE class  {Upstairs,Downstairs,Walking,Jogging,Sitting}    @DATA  -1.18,12.76,1.7297841 ,Upstairs  0.93,10.99,0.08172209 ,Upstairs  0.08,11.35,0.46309182 ,Upstairs  1.88,9.47,3.405087 ,Walking  0.89,9.38,3.3778462 ,Walking  1.38,11.54,3.336985 ,Walking  2.83,3.68,-3.255263 ,Jogging  -1.8,2.45,7.082581 ,Jogging  16.63,9.89,-1.56634 ,Jogging  12.53,1.88,-6.3198414 ,Jogging  7.46,2.3,6.4 ,Sitting  7.5,2.3,6.44 ,Sitting  7.46,2.3,6.47 ,Sitting  -1.23,8.28,0.040861044 ,Downstairs  -1.92,6.28,1.1441092 ,Downstairs  -1.73,5.75,2.152015 ,Downstairs  

the result (i really don't know where that number coming from ):

run:  3.0  BUILD SUCCESSFUL (total time: 1 second)  

there is somthing missing in my code ? if someone can help i will be thankful .

https://stackoverflow.com/questions/67341322/classifying-single-instance-in-weka-multilayerperceptron May 01, 2021 at 06:54AM