public double Run( double[] input )
{
double error = 0.0;
// compute the network
network.Compute( input );
int winner = network.GetWinner( );
// get layer of the network
Layer layer = network.Layers[0];
// check learning radius
if ( learningRadius == 0 )
{
Neuron neuron = layer.Neurons[winner];
// update weight of the winner only
for ( int i = 0; i < neuron.Weights.Length; i++ )
{
// calculate the error
double e = input[i] - neuron.Weights[i];
error += Math.Abs( e );
// update weights
neuron.Weights[i] += e * learningRate;
}
}
else
{
// winner's X and Y
int wx = winner % width;
int wy = winner / width;
// walk through all neurons of the layer
for ( int j = 0; j < layer.Neurons.Length; j++ )
{
Neuron neuron = layer.Neurons[j];
int dx = ( j % width ) - wx;
int dy = ( j / width ) - wy;
// update factor ( Gaussian based )
double factor = Math.Exp( -(double) ( dx * dx + dy * dy ) / squaredRadius2 );
// update weight of the neuron
for ( int i = 0; i < neuron.Weights.Length; i++ )
{
// calculate the error
double e = ( input[i] - neuron.Weights[i] ) * factor;
error += Math.Abs( e );
// update weight
neuron.Weights[i] += e * learningRate;
}
}
}
return error;
}
// Worker thread
void SearchSolution( )
{
// create learning algorithm
SOMLearning trainer = new SOMLearning( network );
// input
double[] input = new double[3];
double fixedLearningRate = learningRate / 10;
double driftingLearningRate = fixedLearningRate * 9;
// iterations
int i = 0;
// loop
while ( !needToStop )
{
trainer.LearningRate = driftingLearningRate * ( iterations - i ) / iterations + fixedLearningRate;
trainer.LearningRadius = (double) radius * ( iterations - i ) / iterations;
input[0] = rand.Next( 256 );
input[1] = rand.Next( 256 );
input[2] = rand.Next( 256 );
trainer.Run( input );
// update map once per 50 iterations
if ( ( i % 10 ) == 9 )
{
UpdateMap( );
}
// increase current iteration
i++;
// set current iteration's info
this.BeginInvoke ( new MethodInvoker (() => currentIterationBox.Text = i.ToString()));
// stop ?
if ( i >= iterations )
break;
}
// enable settings controls
EnableControls( true );
}
