Created Main.java to run the project

Main.java is compiled and executed from the terminal.
It automatically reads the dataset, trains the classififer by creating the VP Tree and runs it over the test dataset to get the accuracy.
Follow steps in the Usage section to run this.

NNClassifier/Main.java

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+/**
+	@author Akshay Mattoo
+*/
+
+package NNClassifier;
+
+import NNClassifier.*;
+import NNClassifier.Classifier.*;
+import NNClassifier.Distance.*;
+import NNClassifier.VPTree.*;
+
+import java.util.*;
+import java.io.*;
+
+public class Main
+{
+	public static void main(String[] args)
+	{
+		//Set Path to Train and Test dataset
+		String trainImagesFile = "NNClassifier/Data/train_images";
+		String trainLabelsFile = "NNClassifier/Data/train_labels";
+		String testImagesFile = "NNClassifier/Data/test_images";
+		String testLabelsFile = "NNClassifier/Data/test_labels";
+
+
+		// Read Train Images
+		System.out.print("Reading train images...");
+		FileInputStream fin = null;
+		ArrayList <Image> trainImages = null;
+		try
+        {
+			fin = new FileInputStream (trainImagesFile);
+			trainImages = readImages (fin);
+			System.out.print("\tRead!\n");
+		}
+        catch (FileNotFoundException e)
+        {
+			System.out.print("\tERROR! File not found\n");
+		}
+
+		// Read Train Labels
+		System.out.print("Reading train labels...");
+		fin = null;
+		ArrayList <Integer> trainLabels = null;
+		try
+        {
+			fin = new FileInputStream (trainLabelsFile);
+			trainLabels = readLabels (fin);
+			System.out.print("\tRead!\n");
+		}
+        catch (FileNotFoundException e)
+        {
+			System.out.print("\tERROR! File not found\n");
+		}
+
+
+		OneNNClassifier classifier = null;
+		System.out.print("Setting distance metric as...");
+		if (args.length==0 || ((String)args[0]).equals("l2"))
+		{
+			l2Distance dist = new l2Distance ();
+			classifier = new OneNNClassifier (dist);
+			System.out.print("\tEuclidean distance\n");
+		}
+		else if (((String)(args[0])).equals("l1"))
+		{
+			l1Distance dist = new l1Distance ();
+			classifier = new OneNNClassifier (dist);
+			System.out.print("\tManhattan distance\n");
+		}
+		else if (((String)(args[0])).equals("linf"))
+		{
+			linfDistance dist = new linfDistance ();
+			classifier = new OneNNClassifier (dist);
+			System.out.print("\tChebyshev distance\n");
+		}
+		else
+		{
+			System.out.print("\tInput not recognized! Using Euclidean distance by default\n");
+			l2Distance dist = new l2Distance ();
+			classifier = new OneNNClassifier (dist);
+		}
+
+
+		// Train Classifier
+		System.out.print("Training classifier...");
+		classifier.train(trainImages, trainLabels);
+		System.out.print("\tDone!\n");
+
+
+		// Read Test Images
+		System.out.print("Reading test images...");
+		fin = null;
+		ArrayList <Image> testImages = null;
+		try
+        {
+			fin = new FileInputStream (testImagesFile);
+			testImages = readImages (fin);
+			System.out.print("\tRead!\n");
+		}
+        catch (FileNotFoundException e)
+        {
+			System.out.print("\tERROR! File not found\n");
+		}
+
+		// Read Test Labels
+		System.out.print("Reading test labels...");
+		fin = null;
+		ArrayList <Integer> testLabels = null;
+		try
+        {
+			fin = new FileInputStream (testLabelsFile);
+			testLabels = readLabels (fin);
+			System.out.print("\tRead!\n");
+		}
+        catch (FileNotFoundException e)
+        {
+			System.out.print("\tERROR! File not found\n");
+		}
+
+
+		System.out.print("Running classifier over test data...");
+		classifier.test (testImages);
+		System.out.print("\tPredictions stored!\n");
+
+
+		System.out.println("Calculating Accuracy...");
+		double acc = classifier.getAccuracy(testLabels);
+		System.out.println("Accuracy = " + acc);
+	}
+
+	private static ArrayList <Image> readImages (FileInputStream fin)
+	{
+        DataInputStream din = new DataInputStream (fin);
+
+        int magicNum = readInt(din);
+		int numItems = readInt(din);
+		int row = readInt(din);
+        int col = readInt(din);
+
+		ArrayList <Image> data = new ArrayList <Image> ();
+		for (int i=0; i<numItems; ++i)
+		{
+			ArrayList <Integer> pixels = new ArrayList <Integer> ();
+			for (int j=0; j<row*col; ++j)
+			{
+				int p = 0;
+                try
+                {
+					p = fin.read();
+				}
+                catch (IOException e)
+                {
+					System.out.println("ERROR! Could not read images");
+				}
+
+				pixels.add(p);
+			}
+
+            Image img = new Image (pixels);
+			data.add(img);
+		}
+		return data;
+	}
+
+	private static ArrayList <Integer> readLabels (FileInputStream fin)
+	{
+        DataInputStream din = new DataInputStream (fin);
+
+        int magicNum = readInt(din);
+		int numItems = readInt(din);
+
+		ArrayList <Integer> labels = new ArrayList <Integer> ();
+		for (int i=0; i<numItems; ++i)
+		{
+            int label = 0;
+            try
+            {
+				label = fin.read();
+			}
+            catch (IOException e)
+            {
+				System.out.println("ERROR! Could not read labels");
+			}
+
+			labels.add(label);
+		}
+		return labels;
+	}
+
+	private static int readInt (DataInputStream din)
+    {
+        try
+        {
+			return din.readInt();
+		}
+        catch (IOException e)
+        {   }
+
+        return 0;
+    }
+
+}