func (h *HiddenLayer) BackwardWithTarget(predicted, target []float64) []float64 {
delta := make([]float64, h.NumHiddenUnits)
for i := 0; i < h.NumHiddenUnits; i++ {
delta[i] = (predicted[i] - target[i]) * nnet.DSigmoid(predicted[i])
}
return delta
}
func (h *HiddenLayer) Backward(predicted, accumulateDelta []float64) []float64 {
delta := make([]float64, h.NumHiddenUnits)
for i := 0; i < h.NumHiddenUnits; i++ {
delta[i] = accumulateDelta[i] * nnet.DSigmoid(predicted[i])
}
return delta
}
func (net *NeuralNetwork) ComputeDelta(predicted,
target []float64) ([]float64, []float64) {
outputDelta := make([]float64, len(net.OutputLayer))
hiddenDelta := make([]float64, len(net.HiddenLayer))
// Output Delta
for i := 0; i < len(net.OutputLayer); i++ {
outputDelta[i] = (predicted[i] - target[i]) *
nnet.DSigmoid(predicted[i])
}
// Hidden Delta
for i := 0; i < len(net.HiddenLayer); i++ {
sum := 0.0
for j := range net.OutputLayer {
sum += net.OutputWeight[i][j] * outputDelta[j]
}
hiddenDelta[i] = sum * nnet.DSigmoid(net.HiddenLayer[i])
}
return outputDelta, hiddenDelta
}