问题
I am trying to classify an instance using Weka in Java (specifically Android Studio). Initially, I saved a model from the Desktop Weka GUI and tried to import it into my project directory. If I am correct, this won't work because the Weka JDKs are different on PC versus Android.
Now I am trying to train a model on the Android itself (as I see no other option) by importing the training dataset. Here is where I am running into problems. When I run "Test.java," I get this error saying that my source hasn't been specified pointing to line 23 where I invoke the .loadDataset method. java.io.IOException: No source has been specified But, clearly, I have specified a path. Is this the correct path? I.E. I am not sure what I am doing wrong. I have looked at other examples/blogs, but none go in detail.
My end goal: train a model in android/java and classify instances in android/java using weka-developed models.
My code can be found at these links:
ModelGenerator.java
package com.example.owner.introductoryapplication;
import android.support.v7.app.AppCompatActivity;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.logging.Level;
import java.util.logging.Logger;
import weka.classifiers.Classifier;
import weka.classifiers.Evaluation;
import weka.classifiers.functions.MultilayerPerceptron;
import weka.core.Instances;
import weka.core.SerializationHelper;
import weka.core.converters.ConverterUtils;
public class ModelGenerator
{
//String trainingSetPath = "JavaTrainingSet.arff"; //com/example/owner/introductoryapplication/JavaTrainingSet.arff
//String modelSavedPath = "com/example/owner/introductoryapplication/JavaTrainingSet.csv";
//Loading dataset from ARFF file and save it to Instances object
public Instances loadDataset(String path)
{
//Declaration and initialization of null training set
Instances dataset = null;
//Loading the dataset into the program
try
{
//Read the dataset
dataset = ConverterUtils.DataSource.read(path);
if (dataset.classIndex() == -1) {
dataset.setClassIndex(dataset.numAttributes() - 1);
}
} catch (Exception ex) {
Logger.getLogger(ModelGenerator.class.getName()).log(Level.SEVERE, null, ex);
}
return dataset;
}
//Building classifier for training set using MultilayerPerceptron (Neural network)
public Classifier buildClassifier(Instances traindataset) {
MultilayerPerceptron m = new MultilayerPerceptron();
try {
m.buildClassifier(traindataset);
} catch (Exception ex) {
Logger.getLogger(ModelGenerator.class.getName()).log(Level.SEVERE, null, ex);
}
return m;
}
//Evaluating the accuracy for the generated model with test set
public String evaluateModel(Classifier model, Instances traindataset, Instances testdataset) {
Evaluation eval = null;
try {
// Evaluate classifier with test dataset
eval = new Evaluation(traindataset);
eval.evaluateModel(model, testdataset);
} catch (Exception ex) {
Logger.getLogger(ModelGenerator.class.getName()).log(Level.SEVERE, null, ex);
}
return eval.toSummaryString("", true);
}
//Saving the generated model to a path to use it for future prediction
public void saveModel(Classifier model, String modelpath) {
try {
SerializationHelper.write(modelpath, model);
} catch (Exception ex) {
Logger.getLogger(ModelGenerator.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
ModelClassifier.java
package com.example.owner.introductoryapplication;
import android.support.v7.app.AppCompatActivity;
import java.util.ArrayList;
import java.util.logging.Level;
import java.util.logging.Logger;
import weka.classifiers.Classifier;
import weka.classifiers.functions.MultilayerPerceptron;
import weka.core.Attribute;
import weka.core.DenseInstance;
import weka.core.Instances;
import weka.core.SerializationHelper;
public class ModelClassifier
{
private Attribute Age;
private Attribute Height;
private Attribute Weight;
private Attribute UPDRS;
private Attribute TUAG;
private Attribute Speed;
private Attribute Gender;
private ArrayList attributes;
private ArrayList classVal;
private Instances dataRaw;
public ModelClassifier() {
Age = new Attribute("Age");
Height = new Attribute("Height");
Weight = new Attribute("Weight");
UPDRS = new Attribute("UPDRS");
TUAG = new Attribute("TUAG");
Speed = new Attribute("Speed");
Gender = new Attribute("Gender");
attributes = new ArrayList();
classVal = new ArrayList();
classVal.add("PD");
classVal.add("CO");
attributes.add(Age);
attributes.add(Height);
attributes.add(Weight);
attributes.add(UPDRS);
attributes.add(TUAG);
attributes.add(Speed);
attributes.add(Gender);
attributes.add(new Attribute("class", classVal));
dataRaw = new Instances("TestInstances", attributes, 0);
dataRaw.setClassIndex(dataRaw.numAttributes() - 1);
}
public Instances createInstance(double Age, double Height, double Weight, double UPDRS, double TUAG, double Speed, double Gender, double result) {
dataRaw.clear();
double[] instanceValue1 = new double[]{Age, Height, 0};
dataRaw.add(new DenseInstance(1.0, instanceValue1));
return dataRaw;
}
public String classifiy(Instances insts, String path) {
String result = "Not classified!!";
Classifier cls = null;
try {
cls = (MultilayerPerceptron) SerializationHelper.read(path);
result = (String) classVal.get((int) cls.classifyInstance(insts.firstInstance()));
} catch (Exception ex) {
Logger.getLogger(ModelClassifier.class.getName()).log(Level.SEVERE, null, ex);
}
return result;
}
public Instances getInstance() {
return dataRaw;
}
}
Test.java
package com.example.owner.introductoryapplication;
import com.example.owner.introductoryapplication.ModelGenerator;
import com.example.owner.introductoryapplication.ModelClassifier;
import android.support.v7.app.AppCompatActivity;
import weka.classifiers.functions.MultilayerPerceptron;
import weka.core.Debug;
import weka.core.Instances;
import weka.filters.Filter;
import weka.filters.unsupervised.attribute.Normalize;
public class Test
{
String DATASETPATH = "com/example/owner/introductoryapplication/JavaTrainingSet.arff";
String MODElPATH = "com/example/owner/introductoryapplication/model.bin";
public static void main(String[] args) throws Exception {
ModelGenerator mg = new ModelGenerator();
Instances dataset = mg.loadDataset("/com/example/owner/introductoryapplication/JavaTrainingSet.arff");
Filter filter = new Normalize();
// divide dataset to train dataset 80% and test dataset 20%
int trainSize = (int) Math.round(dataset.numInstances() * 0.8);
int testSize = dataset.numInstances() - trainSize;
dataset.randomize(new Debug.Random(1));// if you comment this line the accuracy of the model will be droped from 96.6% to 80%
//Normalize dataset
filter.setInputFormat(dataset);
Instances datasetnor = Filter.useFilter(dataset, filter);
Instances traindataset = new Instances(datasetnor, 0, trainSize);
Instances testdataset = new Instances(datasetnor, trainSize, testSize);
// build classifier with train dataset
MultilayerPerceptron ann = (MultilayerPerceptron) mg.buildClassifier(traindataset);
// Evaluate classifier with test dataset
String evalsummary = mg.evaluateModel(ann, traindataset, testdataset);
System.out.println("Evaluation: " + evalsummary);
//Save model
mg.saveModel(ann, "/com/example/owner/introductoryapplication/model.bin");
//classifiy a single instance
ModelClassifier cls = new ModelClassifier();
String classname = cls.classifiy(Filter.useFilter(cls.createInstance(50, 20, 30, 14, 16, 10.42, 2, 0), filter), "/com/example/owner/introductoryapplication/model.bin");
System.out.println("\n The class name for the instance is: " + classname);
System.out.println("\n The class name for the instance is: " + classname);
}
}
A screenshot of where my dataset is right now:
Please let me know at your earliest convenience.
回答1:
Elaborate and in-detail answer is located at this link:
In short, you have to make a raw folder within the res directory. Then save whatever file there. You will access these files per their resource ID's.
来源:https://stackoverflow.com/questions/55443209/unable-to-access-training-dataset-for-ml-classification-using-weka-in-java