Thread: AND Logic Perceptrons

Hello, I've decided to look into the subject of AI programming, and am having trouble with changing my weights with the delta rule. I'm trying to make a simple Boolean AND logic perceptron, which will learn to recognize whether both the inputs are the same.

Here's my code that I have so far:

Code:

// Include header files
#include <iostream>

using namespace std;

int main()
{
	// Delcare vars
	double threshold = 1.0;
	double weight = -0.2;
	double activation;
	int input1, input2;
	bool output;
	
	// Keep looping
	while (1)
	{
		// Get the input vars
		cout << "Please enter the first boolean input: ";
		cin >> input1;
		cout << "Please enter the second boolean input: ";
		cin >> input2;
	
		// Get the activation
		activation = (input1 * weight) + (input2 * weight);
	
		// If the activation is greater than the threshold, fire the perceptron
		if (activation >= threshold)
		{
			cout << "Perceptron is firing" << endl;
			output = true;
		}
		// If the activation is less than the threshold, don't fire
		else if (activation < threshold)
		{
			output = false;
			cout << "Perceptron isn't firing" << endl;	
			cout << "Changing Weights..." << endl;
			cout << "Old Weight: " << weight << endl;
			
			// Change the weights
			weight += (input1 + input2) * (1 - output);
			
			cout << "New Weight: " << weight << endl;
		}
		system("pause");
		system("cls");
	}
	
	return 0;	
}

There is no problem, except once I "train" the perceptron, and the feed it 2 inputs like 1 and 0, it would evaluate to true, but seeing both the inputs aren't true, it shouldn't.

I don't know, but it may be the way I'm adjusting the weights, I'm using the delta rule off the cprogramming tutorials, and I may have interpreted it wrong.

I will admit right now that I'm just starting in this subject, so it's probably some simple mistake, or something that I've overlooked. If anyone has any suggestions, or a solution, it would be appreciated.

Code:

(1 - output);

output is a bool, which is assigned to false a little earlier on. So that's sort of like saying 1.

Therefore,

Code:

weight += (input1 + input2) * (1 - output);

is like

Code:

weight += input1 + input1;

On second thought, you don't even really need output. You only use it once, and where you do, you initialize it just beforehand.

Code:

if (activation >= threshold)
// ...
else if (activation < threshold)

That else if could be an else.