public Vector CalculateAndGetOutput(Vector input, LstmGatesForCell gatesForCell)
{
Input = input;
InputConcatenated = Vector.Union(Input, OutputFromPreviousLayer);
ForgetGateResultF = Sigmoid.Func(gatesForCell.ForgetLayer * InputConcatenated + gatesForCell.BiasForgetLayer);
InputLayerGateResultI = Sigmoid.Func(gatesForCell.InputLayer * InputConcatenated + gatesForCell.BiasInputLayer);
TanhLayerGateResultG = Tanh.Func(gatesForCell.TanhLayer * InputConcatenated + gatesForCell.BiasTanhLayer);
OutputLayerGateResultO = Sigmoid.Func(gatesForCell.OutputLayer * InputConcatenated + gatesForCell.BiasOutputLayer);
Forget = ForgetFromPreviousLayer * ForgetGateResultF + TanhLayerGateResultG * InputLayerGateResultI;
Output = Tanh.Func(Forget) * OutputLayerGateResultO;
return(Output);
}
public (Vector diffOutput, Vector diffForget, Vector diffInput) Learn(Vector diffInputFromNextCell,
Vector diffOutputFromNextLayer, Vector diffForgetFromNextLayer, LstmGatesForCell gatesForCell)
{
var diffOutput = diffInputFromNextCell + diffOutputFromNextLayer;
var one = new Vector(Forget.Length, () => 1);
var diffForget = diffOutput * OutputLayerGateResultO * (one - Tanh.Func(Forget) ^ 2) + diffForgetFromNextLayer;
var(diffTanhGate, diffInputGate, diffForgetGate, diffOutputGate) = GetDiffForGates(diffForget, diffOutput);
gatesForCell.CalculateDiff(diffInputGate, diffForgetGate, diffOutputGate, diffTanhGate, InputConcatenated);
var diffInputConcataneted = GetDiffInputConcataneted(diffInputGate, diffForgetGate, diffOutputGate, diffTanhGate, gatesForCell);
var diffOutputOnNext = diffInputConcataneted.Skip(Input.Length);
var diffInputOnNext = diffInputConcataneted.Take(Input.Length);
var diffForgetOnNext = diffForget * ForgetGateResultF;
return(diffOutputOnNext, diffForgetOnNext, diffInputOnNext);
}
private Vector GetDiffInputConcataneted(Vector diffInputGate, Vector diffForgetGate,
Vector diffOutputGate, Vector diffTanhGate, LstmGatesForCell gatesForCell)
{
var result = gatesForCell.InputLayer.GetTransposed() * diffInputGate;
result += gatesForCell.ForgetLayer.GetTransposed() * diffForgetGate;
result += gatesForCell.OutputLayer.GetTransposed() * diffOutputGate;
result += gatesForCell.TanhLayer.GetTransposed() * diffTanhGate;
return(result);
}
