public void PropagateBackward(NNBackpropagationData backpropagationData)
{
NNTrainingData trainingData = backpropagationData.TrainingData;
// Validate training data dimensions
if (trainingData.InputDataWidth != InputLayer.Width || trainingData.InputDataHeight != InputLayer.Height || trainingData.InputDataDepth != InputLayer.Depth)
{
throw new ArgumentException();
}
if (trainingData.TargetDataWidth != OutputLayer.Width || trainingData.TargetDataHeight != OutputLayer.Height || trainingData.TargetDataDepth != OutputLayer.Depth)
{
throw new ArgumentException();
}
for (int trainingDataIndex = 0; trainingDataIndex < trainingData.DataSize; trainingDataIndex++)
{
backpropagationData.BatchTrainingStartingCallback?.Invoke(trainingDataIndex, trainingData.DataSize);
// Initialize backpropagation run
NNDetailedBackpropagationData detailedBackpropagationData = new NNDetailedBackpropagationData(backpropagationData, trainingDataIndex);
// Feed forward through the network and gather neccessary data
NNFeedData feedForwardInputData = trainingData.GetInputData(trainingDataIndex);
for (int i = 0; i < this.layers.Length; i++)
{
Layer layer = this.layers[i];
NNDetailedFeedData feedData = layer.FeedForward(feedForwardInputData);
detailedBackpropagationData.FeedForwardData[layer] = feedData;
feedForwardInputData = feedData.OutputData;
}
// Propagate error backwards through the network
for (int i = this.layers.Length - 1; i >= 0; i--)
{
Layer layer = this.layers[i];
layer.PropagateBackward(detailedBackpropagationData);
}
// Update weights for each layer
foreach (KeyValuePair <Layer, float[]> updatedWeight in detailedBackpropagationData.UpdatedWeights)
{
Layer layer = updatedWeight.Key;
float[] weights = updatedWeight.Value;
for (int i = 0; i < weights.Length; i++)
{
layer.SetWeight(i, weights[i]);
}
}
backpropagationData.BatchTrainingFinishedCallback?.Invoke(trainingDataIndex, trainingData.DataSize);
}
}
internal static void MaxPoolingTest()
{
InputLayer inputLayer = new InputLayer(20, 20, 2);
MaxPoolingLayer mPLayer = new MaxPoolingLayer(2, 2, inputLayer);
Debug.WriteLine(mPLayer.Width + " " + mPLayer.Height + " " + mPLayer.Depth);
float[,,] inputValues = new float[20, 20, 2];
int i = 0;
for (int z = 0; z < 2; z++)
{
Debug.WriteLine($"{z} --------------------");
for (int y = 0; y < 20; y++)
{
StringBuilder sb = new StringBuilder();
for (int x = 0; x < 20; x++, i++)
{
if (x != 0)
{
sb.Append(", ");
}
inputValues[x, y, z] = i;
sb.Append(i);
}
Debug.WriteLine(sb.ToString());
}
}
NNFeedData inputData = new NNFeedData(inputValues);
NNDetailedFeedData outputData = inputLayer.FeedForward(inputData);
outputData = mPLayer.FeedForward(outputData.OutputData);
for (int z = 0; z < mPLayer.Depth; z++)
{
Debug.WriteLine($"{z} --------------------");
for (int y = 0; y < mPLayer.Height; y++)
{
StringBuilder sb = new StringBuilder();
for (int x = 0; x < mPLayer.Width; x++)
{
if (x != 0)
{
sb.Append(", ");
}
sb.Append($"{outputData.OutputData[outputData.OutputData.ToNeuronIndex(x, y, z)]}");
}
Debug.WriteLine(sb.ToString());
}
}
}
public NNFeedData FeedForward(NNFeedData input)
{
NNFeedData data = input;
for (int i = 0; i < this.layers.Length; i++)
{
Layer layer = this.layers[i];
NNDetailedFeedData feedData = layer.FeedForward(data);
data = feedData.OutputData;
}
return(data);
}
public void TestFeedForward()
{
float[] data = new float[4 * 4 * 2];
for (int i = 0; i < data.Length; i++)
{
data[i] = i + 1;
}
LayerStub prevLayer = new LayerStub(4, 4, 2);
MaxPoolingLayer layer = new MaxPoolingLayer(2, 2, prevLayer);
NNFeedData feedData = new NNFeedData(4, 4, 2, data);
NNDetailedFeedData result = layer.FeedForward(feedData);
Assert.AreEqual(6, result.OutputData[result.OutputData.ToNeuronIndex(0, 0, 0)]);
Assert.AreEqual(8, result.OutputData[result.OutputData.ToNeuronIndex(1, 0, 0)]);
Assert.AreEqual(14, result.OutputData[result.OutputData.ToNeuronIndex(0, 1, 0)]);
Assert.AreEqual(16, result.OutputData[result.OutputData.ToNeuronIndex(1, 1, 0)]);
}
internal override NNDetailedFeedData FeedForward(NNFeedData input)
{
float[] output = new float[Neurons];
int[] maxIndices = new int[Neurons];
for (int zIdx = 0; zIdx < PreviousLayer.Depth; zIdx++)
{
for (int yiIdx = 0, yoIdx = 0; yoIdx < Height; yiIdx += this.Stride, yoIdx++)
{
for (int xiIdx = 0, xoIdx = 0; xoIdx < Width; xiIdx += this.Stride, xoIdx++)
{
float max = float.MinValue;
int maxIdx = -1;
for (int fyIdx = 0; fyIdx < this.FilterSize; fyIdx++)
{
for (int fxIdx = 0; fxIdx < this.FilterSize; fxIdx++)
{
int idx = PreviousLayer.ConvertToNeuronIndex(xiIdx + fxIdx, yiIdx + fyIdx, zIdx);
if (input[idx] > max)
{
max = input[idx];
maxIdx = idx;
}
}
}
int i = ConvertToNeuronIndex(xoIdx, yoIdx, zIdx);
output[i] = max;
maxIndices[i] = maxIdx;
}
}
}
NNDetailedFeedData feedData = new NNDetailedFeedData(this, output, output);
feedData.CustomData[nameof(maxIndices)] = maxIndices;
return(feedData);
}