public void Train(ITrainingDataProvider trainingData, int numEpochs, ITrainingContext context)
{
IMatrix curr = null;
var additionalBackpropagation = trainingData as ICanBackpropagate;
for (int i = 0; i < numEpochs && context.ShouldContinue; i++)
{
context.StartEpoch(trainingData.Count);
trainingData.StartEpoch();
var batchErrorList = new List <double>();
// iterate over each mini batch
foreach (var miniBatch in _GetMiniBatches(trainingData, _stochastic, context.MiniBatchSize))
{
var garbage = new List <IMatrix>();
garbage.Add(curr = miniBatch.Input);
_lap.PushLayer();
// set up the layer stack
var layerStack = new Stack <ICanBackpropagate>();
if (additionalBackpropagation != null)
{
layerStack.Push(additionalBackpropagation);
}
// feed forward
foreach (var layer in _layer)
{
garbage.Add(curr = layer.FeedForward(curr, true));
layerStack.Push(layer);
}
// calculate the error against the training examples
using (var expectedOutput = miniBatch.ExpectedOutput) {
garbage.Add(curr = context.ErrorMetric.CalculateDelta(curr, expectedOutput));
// calculate the training error for this mini batch
if (_calculateTrainingError)
{
batchErrorList.Add(curr.AsIndexable().Values.Select(v => Math.Pow(v, 2)).Average() / 2);
}
// backpropagate the error
while (layerStack.Any())
{
var currentLayer = layerStack.Pop();
garbage.Add(curr = currentLayer.Backpropagate(curr, context, layerStack.Any()));
}
}
// clear memory
context.EndBatch();
garbage.ForEach(m => m?.Dispose());
_lap.PopLayer();
}
context.EndEpoch(_calculateTrainingError ? batchErrorList.Average() : 0f);
}
}
public ExecutionResult Execute(float[] input)
{
_lap.PushLayer();
ExecutionResult ret = null;
_dataSource = new SingleRowDataSource(input, false, MiniBatchSequenceType.Standard, 0);
var provider = new MiniBatchProvider(_dataSource, false);
using (var executionContext = new ExecutionContext(_lap)) {
executionContext.Add(provider.GetMiniBatches(1, mb => _Execute(executionContext, mb)));
IGraphOperation operation;
while ((operation = executionContext.GetNextOperation()) != null)
{
_lap.PushLayer();
operation.Execute(executionContext);
ret = _GetResults().Single();
_ClearContextList();
_lap.PopLayer();
}
}
_lap.PopLayer();
_dataSource = null;
return(ret);
}
