private SimpleLayer[] ComputeMiddleLayers(Sequence pSequence, SimpleLayer[] lastLayers, SimpleLayer forwardLayer,
SimpleLayer backwardLayer)
{
var numStates = lastLayers.Length;
SimpleLayer[] mForward = null;
SimpleLayer[] mBackward = null;
Parallel.Invoke(() =>
{
//Computing forward RNN
forwardLayer.Reset(false);
mForward = new SimpleLayer[lastLayers.Length];
for (var curState = 0; curState < lastLayers.Length; curState++)
{
var state = pSequence.States[curState];
forwardLayer.ForwardPass(state.SparseFeature, lastLayers[curState].Cell);
mForward[curState] = forwardLayer.CloneHiddenLayer();
}
},
() =>
{
//Computing backward RNN
backwardLayer.Reset(false);
mBackward = new SimpleLayer[lastLayers.Length];
for (var curState = lastLayers.Length - 1; curState >= 0; curState--)
{
var state = pSequence.States[curState];
backwardLayer.ForwardPass(state.SparseFeature, lastLayers[curState].Cell);
mBackward[curState] = backwardLayer.CloneHiddenLayer();
}
});
//Merge forward and backward
var mergedLayer = new SimpleLayer[numStates];
Parallel.For(0, numStates, parallelOption, curState =>
{
var state = pSequence.States[curState];
mergedLayer[curState] = new SimpleLayer(forwardLayer.LayerConfig)
{
SparseFeature = state.SparseFeature,
DenseFeature = lastLayers[curState].Cell
};
var forwardCells = mForward[curState];
var backwardCells = mBackward[curState];
var i = 0;
while (i < forwardLayer.LayerSize - Vector <float> .Count)
{
var v1 = new Vector <float>(forwardCells.Cell, i);
var v2 = new Vector <float>(backwardCells.Cell, i);
var v = (v1 + v2) / vecConst2;
v.CopyTo(mergedLayer[curState].Cell, i);
i += Vector <float> .Count;
}
while (i < forwardLayer.LayerSize)
{
mergedLayer[curState].Cell[i] =
(float)((forwardCells.Cell[i] + backwardCells.Cell[i]) / 2.0);
i++;
}
});
return(mergedLayer);
}
/// <summary>
/// Compute the output of bottom layer
/// </summary>
/// <param name="pSequence"></param>
/// <param name="forwardLayer"></param>
/// <param name="backwardLayer"></param>
/// <returns></returns>
private SimpleLayer[] ComputeBottomLayer(Sequence pSequence, SimpleLayer forwardLayer, SimpleLayer backwardLayer)
{
var numStates = pSequence.States.Length;
SimpleLayer[] mForward = null;
SimpleLayer[] mBackward = null;
Parallel.Invoke(() =>
{
//Computing forward RNN
forwardLayer.Reset(false);
mForward = new SimpleLayer[numStates];
for (var curState = 0; curState < numStates; curState++)
{
var state = pSequence.States[curState];
SetRuntimeFeatures(state, curState, numStates, null);
forwardLayer.ForwardPass(state.SparseFeature, state.DenseFeature.CopyTo());
mForward[curState] = forwardLayer.CloneHiddenLayer();
}
},
() =>
{
//Computing backward RNN
backwardLayer.Reset(false);
mBackward = new SimpleLayer[numStates];
for (var curState = numStates - 1; curState >= 0; curState--)
{
var state = pSequence.States[curState];
SetRuntimeFeatures(state, curState, numStates, null, false);
backwardLayer.ForwardPass(state.SparseFeature, state.DenseFeature.CopyTo());
//compute probability distribution
mBackward[curState] = backwardLayer.CloneHiddenLayer();
}
});
var mergedLayer = new SimpleLayer[numStates];
Parallel.For(0, numStates, parallelOption, curState =>
{
var state = pSequence.States[curState];
mergedLayer[curState] = new SimpleLayer(forwardLayer.LayerConfig)
{
SparseFeature = state.SparseFeature,
DenseFeature = state.DenseFeature.CopyTo()
};
var forwardCells = mForward[curState];
var backwardCells = mBackward[curState];
var i = 0;
while (i < forwardLayer.LayerSize - Vector <float> .Count)
{
var v1 = new Vector <float>(forwardCells.Cell, i);
var v2 = new Vector <float>(backwardCells.Cell, i);
var v = (v1 + v2) / vecConst2;
v.CopyTo(mergedLayer[curState].Cell, i);
i += Vector <float> .Count;
}
while (i < forwardLayer.LayerSize)
{
mergedLayer[curState].Cell[i] =
(float)((forwardCells.Cell[i] + backwardCells.Cell[i]) / 2.0);
i++;
}
});
return(mergedLayer);
}