/// <summary>
/// Extract features from source sequence
/// </summary>
/// <param name="decoder"></param>
/// <param name="srcSequence"></param>
/// <param name="targetSparseFeatureSize"></param>
/// <param name="srcHiddenAvgOutput"></param>
/// <param name="srcSparseFeatures"></param>
protected virtual void ExtractSourceSentenceFeature(RNNDecoder decoder, Sequence srcSequence, int targetSparseFeatureSize)
{
//Extract dense features from source sequence
var srcOutputs = decoder.ComputeTopHiddenLayerOutput(srcSequence);
int srcSequenceDenseFeatureSize = srcOutputs[0].Length;
int srcSequenceLength = srcOutputs.Length - 1;
if (srcHiddenAvgOutput == null)
{
srcHiddenAvgOutput = new float[srcSequenceDenseFeatureSize * 2];
}
var j = 0;
float[] srcOutputForward = srcOutputs[0];
float[] srcOutputBackward = srcOutputs[srcSequenceLength];
while (j < srcSequenceDenseFeatureSize)
{
var vForward = new Vector <float>(srcOutputForward, j);
var vBackward = new Vector <float>(srcOutputBackward, j);
vForward.CopyTo(srcHiddenAvgOutput, j);
vBackward.CopyTo(srcHiddenAvgOutput, srcSequenceDenseFeatureSize + j);
j += Vector <float> .Count;
}
//Extract sparse features from source sequence
if (srcSparseFeatures == null)
{
srcSparseFeatures = new Dictionary <int, float>();
}
else
{
srcSparseFeatures.Clear();
}
for (var i = 0; i < srcSequence.States.Length; i++)
{
foreach (var kv in srcSequence.States[i].SparseFeature)
{
var srcSparseFeatureIndex = kv.Key + targetSparseFeatureSize;
if (srcSparseFeatures.ContainsKey(srcSparseFeatureIndex) == false)
{
srcSparseFeatures.Add(srcSparseFeatureIndex, kv.Value);
}
else
{
srcSparseFeatures[srcSparseFeatureIndex] += kv.Value;
}
}
}
}
/// <summary>
/// Extract features from source sequence
/// </summary>
/// <param name="decoder"></param>
/// <param name="srcSequence"></param>
/// <param name="targetSparseFeatureSize"></param>
/// <param name="srcHiddenAvgOutput"></param>
/// <param name="srcSparseFeatures"></param>
private void ExtractSourceSentenceFeature(RNNDecoder decoder, Sequence srcSequence, int targetSparseFeatureSize, List <float[]> srcDenseFeatureGroups, SparseVector srcSparseFeatures)
{
//Extract dense features from source sequence
var srcOutputs = decoder.ComputeTopHiddenLayerOutput(srcSequence);
int srcSequenceLength = srcOutputs.Length - 1;
srcDenseFeatureGroups.Add(srcOutputs[srcSequenceLength]);
if (numSrcDenseFeatureGroups > 1)
{
srcDenseFeatureGroups.Add(srcOutputs[0]);
}
if (numSrcDenseFeatureGroups > 2)
{
float srcOffsetPerBlock = (float)srcSequenceLength / (float)(numSrcDenseFeatureGroups - 1);
if (srcOffsetPerBlock < 1.0)
{
srcOffsetPerBlock = 1.0f;
}
float idx = srcOffsetPerBlock;
while (srcDenseFeatureGroups.Count < numSrcDenseFeatureGroups && idx < srcSequenceLength)
{
srcDenseFeatureGroups.Add(srcOutputs[(int)idx]);
idx += srcOffsetPerBlock;
}
}
//Extract sparse features from source sequence
Dictionary <int, float> srcSparseFeaturesDict = new Dictionary <int, float>();
for (var i = 0; i < srcSequence.States.Length; i++)
{
foreach (var kv in srcSequence.States[i].SparseFeature)
{
var srcSparseFeatureIndex = kv.Key + targetSparseFeatureSize;
if (srcSparseFeaturesDict.ContainsKey(srcSparseFeatureIndex) == false)
{
srcSparseFeaturesDict.Add(srcSparseFeatureIndex, kv.Value);
}
else
{
srcSparseFeaturesDict[srcSparseFeatureIndex] += kv.Value;
}
}
}
srcSparseFeatures.SetLength(srcSequence.SparseFeatureSize + targetSparseFeatureSize);
srcSparseFeatures.AddKeyValuePairData(srcSparseFeaturesDict);
}
