c++ assignment

main.cpp

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

/* 
 * File:   main.cpp
 * Author: dube_
 *
 * Created on 30 August 2018, 10:34 PM
 */

#include <cstdlib>
#include <iostream>
#include "neuron.h"
#include <cmath>

using namespace std;
float LR = 0.1;
float get_error(float output, float target) {
	return output * (1 - output) * (target - output);
}

vector<float> get_hidden_node_error(vector<neuron>& hidden_nodes,
		vector<neuron>& out, vector<float>& inputs, vector<float>& o_error) {
	vector<float> errors(hidden_nodes.size());
	for (int i = 0; i < hidden_nodes.size(); ++i) {
		float oh = hidden_nodes[i].guess(inputs);
		float summation = 0;
		/**performing the summation with the output weights*/
		summation += (out[0].get_weights()[i] * o_error[0]);
		errors[i] = oh * (1 - oh) * summation;
	}
	return errors;
}

void update_weightings(vector<neuron>& output, vector<float>& error,
		vector<float>& input) {
//	cout << "here" << endl;
	float delta;
	for (int i = 0; i < error.size(); i++) {
		for (int j = 0; j < input.size(); j++) {
			delta = LR * error[i] * input[j];
			output[i].weights[j] += delta;
		}
	}

}

vector<vector<float>> generate_input() {
	vector<vector<float>> inputs = { { 0, 0, 0 }, { 0, 0, 1 }, { 0, 1, 0 }, { 0,
			1, 1 }, { 1, 0, 0 }, { 1, 0, 1 }, { 1, 1, 0 }, { 1, 1, 1 } };
	return inputs;
}
float RandomFloat(float a, float b) {
	float random = ((float) rand()) / (float) RAND_MAX;
	float diff = b - a;
	float r = random * diff;
	return a + r;
}
/**code from stacks overflow*/
vector<float> generate_weights() {
	vector<float> weights(3);
	for (int i = 0; i < 3; ++i) {
		weights[i] = RandomFloat(-3, 3);
	}
	return weights;
}

float calcMeanSquaredError(vector<float>& outputs, vector<float>& targets) {
	float sumation = 0;
	for (int i = 0; i < outputs.size(); ++i) {
		sumation += powf((outputs[i] - targets[i]), 2);
	}
	return sumation * 0.5;
}
float calcMeanSquaredError(float outputs, float targets) {
		float sumation = 0;
		sumation += powf((outputs - targets), 2);
		return sumation * 0.5;
}

void run() {
	neuron hidden1(generate_weights());
	neuron hidden2(generate_weights());
	neuron hidden3(generate_weights());
	vector<neuron> hidden_nodes = { hidden1, hidden2, hidden3 };
//    vector<neuron> hidden_nodes = { hidden1};
	cout << "Hidden layer weights" << endl;
	for (neuron n : hidden_nodes) {
		for (float f : n.get_weights()) {
			cout << f << endl;
		}
		cout << endl;
	}
	neuron y1(generate_weights());
	cout << "\nOutput Layer weights" << endl;
	for (float f : y1.get_weights()) {
		cout << f << endl;
	}
	vector<neuron> outputs = { y1 };
	vector<float> targets = { 0, 1, 1, 0, 1, 0, 0, 1 };
	vector<float> outputs_vector;
	vector<vector<float>> inputs = generate_input(); //get the vector of input vectors
//ado{
	for (int i = 0; i < inputs.size(); ++i) {
		float meanSQ=0;
		for (int j = 0; j < 2000; j++) {
//			vector<float> a = { hidden1.guess(inputs[i])};
			vector<float> a = { hidden1.guess(inputs[i]), hidden2.guess(
					inputs[i]), hidden3.guess(inputs[i])}; //vector of outputs of the hidden layer
			vector<float> output = { outputs[0].guess(a) };
			vector<float> o_error = { get_error(output[0], targets[i]) };
			cout<<"Output : "<<output[0]<< " targets is: " <<targets[i] <<endl;
			vector<float> hidden_node_erros(
					get_hidden_node_error(hidden_nodes, outputs, inputs[i],
							o_error));
			update_weightings(outputs, o_error, a);
			update_weightings(hidden_nodes, hidden_node_erros, inputs[i]);
			meanSQ = calcMeanSquaredError(output[0], targets[i]);
		} //while();
		cout<<"Mean Squared error: "<<meanSQ<<endl;
//		cout << "\n" << calcMeanSquaredError(outputs_vector, targets) << endl;
	}
	cout << "\nupdated output weights" << endl;
	for (float f : outputs[0].get_weights()) {
		cout << f << endl;
	}

	cout << "\nUpdated Hidden layer weights" << endl;
	for (neuron n : hidden_nodes) {
		for (float f : n.get_weights()) {
			cout << f << endl;
		}
		cout << endl;
	}
}

/*
 *
 */
int main(int argc, char** argv) {
	run();
	return 0;
}