Machine Learning Sample Code with OpenCV 3.0 for Android

MLTest.java

import android.util.Log;

import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.ml.LogisticRegression;

public class MLTest {
    private final static String TAG = MLTest.class.getSimpleName();

    MLTest() {
        run();
    }

    void run() {
        float[][] trainingData = new float[][]{{501f, 10f}, {255f, 10f}, {501f, 255f}, {10f, 501f}};
        Mat trainingDataMat = new Mat(4, 2, CvType.CV_32FC1);
        for (int i = 0; i < trainingData.length; i++) {
            for (int j = 0; j < trainingData[i].length; j++) {
                trainingDataMat.put(i, j, trainingData[i][j]);
            }
        }

        float[] labels = new float[]{1.0f, 2.0f, 1.0f, 2.0f};
        Mat labelsMat= new Mat(4, 1, CvType.CV_32FC1);
        for (int i = 0; i < trainingData.length; i++) {
            labelsMat.put(i, 0, labels[i]);
        }

        float[] testData = new float[]{502f, 10f};
        Mat testDataMat = new Mat(1, 2, CvType.CV_32FC1);
        for (int i = 0; i < testData.length; i++) {
            testDataMat.put(0, i, testData[i]);
        }

        Mat resultMat = new Mat(1, 1, CvType.CV_32SC1);

        LogisticRegression clf = LogisticRegression.create();
        clf.train(trainingDataMat, 0, labelsMat);
        clf.predict(testDataMat, resultMat, 0);
        Log.i(TAG, String.format("predicted: %f", (float)resultMat.get(0, 0)[0]));
    }
}