private static void AlphabetRecognition()
{
double[][] testInput = AlphabetData.Samples.Select(s => s.Input).ToArray();
double[][] testOutput = AlphabetData.Samples.Select(s => new double[] { s.Output }).ToArray();
BackPropNeuralNetwork network = new BackPropNeuralNetwork(15, 20, 1);
network.Initialize();
BackPropNeuralNetworkTrainer trainer = new BackPropNeuralNetworkTrainer(100000, 0.3, 0.1, maxAllowedError);
if (trainer.TrainNetwork(network, testInput, testOutput))
{
string fileName = "AlphabetRecognition_" + DateTime.Now.ToString("yyMMdd-HHmmss") + ".nnetwork";
using (Stream stream = File.Create(fileName))
{
BinaryFormatter formatter = new BinaryFormatter();
formatter.Serialize(stream, network);
}
BackPropNeuralNetwork newNetwork;
using (Stream stream = File.OpenRead(fileName))
{
BinaryFormatter formetter = new BinaryFormatter();
newNetwork = (BackPropNeuralNetwork)formetter.Deserialize(stream);
}
}
}
public bool TrainNetwork(BackPropNeuralNetwork network, double[][] inputValues, double[][] targetValues)
{
// TODO: check array lenghts agains network params
double[] currentResult;
double iterationError;
double[] currentInput;
double[] targetOutput;
double[] sampleErrors = new double[inputValues.Length];
Stopwatch watch = new Stopwatch();
for (int iteration = 0; iteration < maxIterations; iteration++)
{
if (iteration % 20 == 0)
{
watch.Restart();
// TODO: broadcast progress
Console.Write("Training iteration " + iteration + "...");
//Console.WriteLine("Errors: "+string.Join(" ", sampleErrors));
}
bool allClear = true;
for (int sampleIndex = 0; sampleIndex < inputValues.Length; sampleIndex++)
{
currentInput = inputValues[sampleIndex];
targetOutput = targetValues[sampleIndex];
currentResult = network.Run(currentInput);
iterationError = CalculateError(currentResult, targetOutput);
sampleErrors[sampleIndex] = iterationError;
if (iterationError >= this.maxAllowedError)
{
allClear = false;
network.UpdateWeights(targetOutput, this.learningRate, this.momentum);
}
}
if (iteration % 20 == 0)
{
watch.Stop();
Console.WriteLine("\b\b\b took " + watch.Elapsed.ToString());
}
if (allClear)
{
// TODO: success!
Console.WriteLine("Training complete at iteration " + iteration);
return(true);
}
}
return(false);
}
