/// <summary>
/// Run forward part on given single device
/// </summary>
/// <param name="g">The computing graph for current device. It gets created and passed by the framework</param>
/// <param name="srcSnts">A batch of input tokenized sentences in source side</param>
/// <param name="tgtSnts">A batch of output tokenized sentences in target side. In training mode, it inputs target tokens, otherwise, it outputs target tokens generated by decoder</param>
/// <param name="deviceIdIdx">The index of current device</param>
/// <returns>The cost of forward part</returns>
public override List <NetworkResult> RunForwardOnSingleDevice(IComputeGraph g, ISntPairBatch sntPairBatch, int deviceIdIdx, bool isTraining, DecodingOptions decodingOptions)
{
List <NetworkResult> nrs = new List <NetworkResult>();
var srcSnts = sntPairBatch.GetSrcTokens(0);
var tgtSnts = sntPairBatch.GetTgtTokens(0);
(IEncoder encoder, IWeightTensor srcEmbedding, IWeightTensor posEmbedding, FeedForwardLayer decoderFFLayer) = GetNetworksOnDeviceAt(deviceIdIdx);
// Reset networks
encoder.Reset(g.GetWeightFactory(), srcSnts.Count);
var originalSrcLengths = BuildInTokens.PadSentences(srcSnts);
var srcTokensList = m_modelMetaData.SrcVocab.GetWordIndex(srcSnts);
BuildInTokens.PadSentences(tgtSnts);
var tgtTokensLists = m_modelMetaData.ClsVocab.GetWordIndex(tgtSnts);
int seqLen = srcSnts[0].Count;
int batchSize = srcSnts.Count;
// Encoding input source sentences
IWeightTensor encOutput = Encoder.Run(g, sntPairBatch, encoder, m_modelMetaData, m_shuffleType, srcEmbedding, posEmbedding, null, srcTokensList, originalSrcLengths);
IWeightTensor ffLayer = decoderFFLayer.Process(encOutput, batchSize, g);
float cost = 0.0f;
IWeightTensor probs = g.Softmax(ffLayer, inPlace: true);
if (isTraining)
{
var tgtTokensTensor = g.CreateTokensTensor(tgtTokensLists);
cost = g.CrossEntropyLoss(probs, tgtTokensTensor);
}
else
{
// Output "i"th target word
using var targetIdxTensor = g.Argmax(probs, 1);
float[] targetIdx = targetIdxTensor.ToWeightArray();
List <string> targetWords = m_modelMetaData.ClsVocab.ConvertIdsToString(targetIdx.ToList());
for (int k = 0; k < batchSize; k++)
{
tgtSnts[k] = targetWords.GetRange(k * seqLen, seqLen);
}
}
NetworkResult nr = new NetworkResult
{
Cost = cost,
Output = new List <List <List <string> > >()
};
nr.Output.Add(tgtSnts);
nrs.Add(nr);
return(nrs);
}