public void multiply <Type>(Type n)
{
if (n is NNMatrix)
{
for (int i = 0; i < this.rows; i++)
{
for (int j = 0; j < this.cols; j++)
{
NNMatrix mat = (NNMatrix)(object)n;
this.data[i][j] *= mat.data[i][j];
}
}
}
else
{
for (int i = 0; i < this.rows; i++)
{
for (int j = 0; j < this.cols; j++)
{
float val = (float)(object)n;
this.data[i][j] *= val;
}
}
}
}
public static NNMatrix multiply(NNMatrix a, NNMatrix b)
{
if (a.cols != b.rows)
{
Debug.Log("Columns of A must match rows of B.");
return(null);
}
NNMatrix result = new NNMatrix(a.rows, b.cols);
for (int i = 0; i < result.rows; i++)
{
for (int j = 0; j < result.cols; j++)
{
float sum = 0f;
for (int k = 0; k < a.cols; k++)
{
sum += a.data[i][k] * b.data[k][j];
}
result.data[i][j] = sum;
}
}
return(result);
}
public void train(List <float> input_list, List <float> target_list)
{
NNMatrix inputs = NNMatrix.fromList(input_list);
NNMatrix hidden = NNMatrix.multiply(this.weights_ih, inputs);
hidden.add(this.bias_h);
// activate function
hidden.map(activate);
NNMatrix outputs = NNMatrix.multiply(this.weights_ho, hidden);
outputs.add(this.bias_o);
outputs.map(activate);
NNMatrix targets = NNMatrix.fromList(target_list);
// calculate the error
// ERROR = TARGETS(answer) - OUTPUTS(actual outputs)
NNMatrix output_errors = NNMatrix.subtract(targets, outputs);
//var gradients = outputs * (1-outputs);
// calculate gradient
NNMatrix gradients = NNMatrix.map(outputs, dactivate);
gradients.multiply(output_errors);
gradients.multiply(this.learning_rate);
// calculate deltas
NNMatrix hidden_T = NNMatrix.transpose(hidden);
NNMatrix weights_ho_deltas = NNMatrix.multiply(gradients, hidden_T);
// Adjust the weights by deltas
this.weights_ho.add(weights_ho_deltas);
// Adjust bias by its delta (which is just the gradients)
this.bias_o.add(gradients);
// calculate the hidden layer errors
NNMatrix who_t = NNMatrix.transpose(this.weights_ho);
NNMatrix hidden_errors = NNMatrix.multiply(who_t, output_errors);
// calculate hidden gradients
NNMatrix hidden_gradient = NNMatrix.map(hidden, dactivate);
hidden_gradient.multiply(hidden_errors);
hidden_gradient.multiply(this.learning_rate);
// calculate input->hidden deltas
NNMatrix input_T = NNMatrix.transpose(inputs);
NNMatrix weight_ih_deltas = NNMatrix.multiply(hidden_gradient, input_T);
this.weights_ih.add(weight_ih_deltas);
// Adjust bias by its delta (which is just the hiddent gradients)
this.bias_h.add(hidden_gradient);
}
public static NNMatrix fromList(List <float> list)
{
NNMatrix m = new NNMatrix(list.Count, 1);
for (int i = 0; i < list.Count; i++)
{
m.data[i][0] = list[i];
}
return(m);
}
public static NNMatrix subtract(NNMatrix a, NNMatrix b)
{
NNMatrix result = new NNMatrix(a.rows, a.cols);
for (int i = 0; i < result.rows; i++)
{
for (int j = 0; j < result.cols; j++)
{
result.data[i][j] = a.data[i][j] - b.data[i][j];
}
}
return(result);
}
public static NNMatrix transpose(NNMatrix matrix)
{
NNMatrix result = new NNMatrix(matrix.cols, matrix.rows);
for (int i = 0; i < matrix.rows; i++)
{
for (int j = 0; j < matrix.cols; j++)
{
result.data[j][i] = matrix.data[i][j];
}
}
return(result);
}
public static NNMatrix map(NNMatrix matrix, System.Func <float, float> func)
{
NNMatrix result = new NNMatrix(matrix.rows, matrix.cols);
for (int i = 0; i < matrix.rows; i++)
{
for (int j = 0; j < matrix.cols; j++)
{
float val = matrix.data[i][j];
result.data[i][j] = func(val);
}
}
return(result);
}
public NeuralNetwork(int _input_nodes, int _hidden_nodes, int _output_nodes)
{
this.input_nodes = _input_nodes;
this.hidden_nodes = _hidden_nodes;
this.output_nodes = _output_nodes;
// weight between input and hidden
this.weights_ih = new NNMatrix(this.hidden_nodes, this.input_nodes);
this.weights_ih.randomize();
// weight between hidden and output
this.weights_ho = new NNMatrix(this.output_nodes, this.hidden_nodes);
this.weights_ho.randomize();
this.bias_h = new NNMatrix(this.hidden_nodes, 1);
this.bias_o = new NNMatrix(this.output_nodes, 1);
}
// feedforward
public List <float> predict(List <float> input_list)
{
NNMatrix inputs = NNMatrix.fromList(input_list);
NNMatrix hidden = NNMatrix.multiply(this.weights_ih, inputs);
hidden.add(this.bias_h);
// activate function
hidden.map(activate);
NNMatrix output = NNMatrix.multiply(this.weights_ho, hidden);
output.add(this.bias_o);
output.map(activate);
return(output.toList());
}
public NeuralNetwork copy()
{
int _input_nodes = this.input_nodes;
int _hidden_nodes = this.hidden_nodes;
int _output_nodes = this.output_nodes;
NNMatrix wih = this.weights_ih;
NNMatrix who = this.weights_ho;
float lr = this.learning_rate;
NNMatrix bh = this.bias_h;
NNMatrix oh = this.bias_o;
NeuralNetwork nn = new NeuralNetwork(_input_nodes, _hidden_nodes, _output_nodes);
nn.weights_ih = wih;
nn.weights_ho = who;
nn.learning_rate = lr;
nn.bias_h = bh;
nn.bias_o = oh;
return(nn);
}
public void mutate()
{
this.weights_ih = NNMatrix.map(this.weights_ih, NNUtils.mutate);
this.weights_ho = NNMatrix.map(this.weights_ho, NNUtils.mutate);
}