From 907f19b0761c7a3e7da84fa6f1854c9317c98b21 Mon Sep 17 00:00:00 2001
From: Marco Raber <marco.raber@tutanota.com>
Date: Wed, 26 Jan 2022 20:11:01 +0100
Subject: [PATCH] siamo a buon punto nella back-prop ma mannaggia a quanto sei
 tedesco java

---
 XOR.java | 189 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 189 insertions(+)
 create mode 100644 XOR.java

diff --git a/XOR.java b/XOR.java
new file mode 100644
index 0000000..1b2a494
--- /dev/null
+++ b/XOR.java
@@ -0,0 +1,189 @@
+import java.text.DecimalFormat;
+
+public class XOR{
+
+	private static double fdt(double x,Boolean deriv){
+		if (deriv)	return x*(1-x);
+		return 1/(1+Math.exp(-x));
+	}
+
+	//applica fdt a una matrice
+	private static double[][] fdt_mat(double[][] x,Boolean deriv){
+		if (deriv) {
+			for(int i=0; i<x.length; i++){
+				for(int j=0; j<x[0].length; j++){
+					x[i][j] = x[i][j]*(1-x[i][j]);
+				}
+			}
+		}
+		else {
+			for(int i=0; i<x.length; i++){
+				for(int j=0; j<x[0].length; j++){
+					x[i][j] = 1/(1+Math.exp(-x[i][j]));
+				}
+			}
+		}
+		return x;
+	}
+
+	//funzione per traslare invece di for{for{}}
+	private static double[][] translate(double[][] matrix){
+		double[][] Tmatrix = new double[matrix[0].length][matrix.length];
+		for(int i=0; i<Tmatrix.length; i++){
+			for(int j=0; j<Tmatrix[0].length; j++){
+				Tmatrix[i][j] = matrix[j][i];
+			}
+		}
+		return Tmatrix;
+	}
+
+	private static double[][] dot_product(double[][] firstMatrix, double[][] secondMatrix) {
+		int r1 = firstMatrix.length;
+		int c1 = firstMatrix[0].length;
+		int r2 = secondMatrix.length;
+		int c2 = secondMatrix[0].length;
+		double[][] product = new double[r1][c2];
+		for(int i = 0; i < r1; i++) {
+		    for (int j = 0; j < c2; j++) {
+			for (int k = 0; k < c1; k++) {
+			    product[i][j] += firstMatrix[i][k] * secondMatrix[k][j];
+			}
+		    }
+		}
+
+		return product;
+	}
+
+	private static void stampa_matrice(double matrix[][]){
+		DecimalFormat numberFormat = new DecimalFormat("#.000");
+		for(int i=0; i<matrix.length; i++){
+			for(int j=0; j<matrix[0].length; j++){
+				System.out.print(numberFormat.format(matrix[i][j])+"\t"); //3 decimali
+				//System.out.print((matrix[i][j])+"\t"); //tutti i decimali
+			}
+			//System.out.print(" ");
+			System.out.println("\n");
+		}
+	}
+
+	public static void main(String args[]){
+		int iterazioni = 1000000;
+		int hidden_layer = 5;
+		double epsilon = 0.001;
+		if (args.length > 0) iterazioni=Integer.parseInt(args[0]);
+		//Matrice degli input, 4x3
+		double X[][] = {
+			{0d,0d,1d},
+			{0d,1d,1d},
+			{1d,0d,1d},
+			{1d,1d,1d}
+		};
+
+		//Matrice degli output desiderati \xi, 4x1, una riga per ogni esempio
+		double Y[][] = { 
+			{0d},
+			{1d},
+			{1d},
+			{0d}
+			};
+		double Ytest[][] = { 
+			{1d},
+			{0d},
+			{0d},
+			{1d}
+			};
+
+		//synapsi, primo set, 3x4
+		double[][] syn0 = new double[X[0].length][hidden_layer];
+		syn0 = randomize_matrix(syn0);
+		
+		//synapsi, secondo set, 4x1
+		double[][] syn1 = new double[hidden_layer][1];
+		syn1 = randomize_matrix(syn1);
+
+		//fase forward iniziale
+		double[][] l0 = X;
+		double[][] l1 = dot_product(l0,syn0);
+		double[][] l2 = dot_product(l1,syn1);
+
+		for(int iter=0; iter<iterazioni; iter++){ //main cycle
+			double old_error = error_func(l2,Y);
+
+			double[][] delta_nu = subtract_matrix_ebe(Y , l2);
+
+
+			double delta_W = 0; //batch
+			for(int j=0;j<hidden_layer; j++){ //aggiornamento delle sinapsi del Perceptron di output
+				for(int nu=0;nu<X.length; nu++){
+					double [][] y_nu = new double[1][l1[nu].length];
+					for(int y=0;y<l1[nu].length; y++){ y_nu[0][y] = l1[nu][y]; }
+					delta_W += epsilon*delta_nu[nu][0]*fdt(dot_product(y_nu,syn1)[0][0],true)*l1[nu][j];
+				}
+				syn1[j][0] += delta_W;
+			}
+
+			double[][] syn0_transposed = new double[syn0[0].length][syn0.length];
+			for(int i=0;i<syn0_transposed.length;i++){ 
+				for(int j=0;j<syn0_transposed[0].length; j++){ 
+					syn0_transposed[i][j] = syn0[j][i];
+				}
+
+			}
+
+
+			double delta_wij = 0;
+			for(int i=0;i<X[0].length;i++){ //loop sugli input
+				for(int j=0;j<hidden_layer; j++){ //loop sui neuroni dello strato hidden
+					for(int nu=0;nu<X.length; nu++){
+						double [][] y_nu = new double[1][l1[nu].length];
+						for(int y=0;y<l1[nu].length; y++){ y_nu[0][y] = l1[nu][y]; }
+						double [][] X_row = new double[1][X[nu].length];
+						double [][] syn0_transposed_row = new double[1][X[nu].length];
+						for(int y=0;y<X[nu].length; y++){
+							syn0_transposed_row[0][y] = syn0_transposed[nu][y];
+							X_row[0][y] = X[nu][y];
+
+						}
+						//delta_wij += epsilon*delta_nu[nu][0]*fdt(dot_product(y_nu,syn1)[0][0],true)*syn1[j][0]*fdt(dot_product(X_row,syn0_transposed[j])[0][0],true)*X[nu][i];
+						//OUT OF BOUNDS PER QUALCHE MOTIVO
+						//stampa_matrice(dot_product(X_row,syn0_transposed_row));
+					}
+					syn1[j][0] += delta_wij;
+				}
+
+			}
+			
+		}
+
+
+
+	}
+
+	private static double[][] randomize_matrix(double[][] mat){ //prende matrice e mette numero randomico in celle
+		for(int i=0; i<mat.length; i++){
+			for(int j=0; j<mat[0].length; j++){
+				mat[i][j] = 0.1*Math.random();
+			}
+		}
+		return mat;
+	}
+					//ELEMENT BY ELEMENT
+	private static double[][] subtract_matrix_ebe(double[][] mat1, double[][] mat2){ //sottrazione di matrici termine a termine
+		double[][] mat = new double[mat1.length][mat1[0].length];
+		for(int i=0; i<mat.length; i++){
+			for(int j=0; j<mat[0].length; j++){
+				mat[i][j] = mat1[i][j] - mat2[i][j];
+			}
+		}
+		return mat;
+	}
+
+	private static double error_func(double[][] output, double[][] xi){ //calcolo di errore di output di rete
+		double e=0;
+		for(int i=0; i<output.length; i++){
+			e += Math.pow((output[i][0] - xi[i][0]),2);
+		}
+		return 0.5*e;
+	}
+}
+