public float TrainOne(Sent sent)
{
G.Need = true;
var c = new ArcStandardConfig(sent, false, _rngChoice);
GetTokenRepr(sent, true);
var losses = 0f;
while (!c.IsTerminal())
{
var oracle = c.GetOracle(_conf.OraType, out float[] target, out string slabel);
GetTrans(c, out Tensor op, out Tensor label);
G.SoftmaxWithCrossEntropy(op, target, out float loss);
losses += loss;
if (slabel != null)
{
// in mapping 0 is unk, 1 is root
var labelid = _train.DepLabel[slabel] - 1;
G.SoftmaxWithCrossEntropy(label, labelid, out loss);
losses += loss;
}
c.Apply(oracle, slabel);
}
G.Backward();
_opt.Update(FixedParams);
_opt.Update(VariedParams);
VariedParams.Clear();
G.Clear();
return(losses / sent.Count);
}
private void GetTokenRepr(Sent sent, bool grad)
{
var x = new Tensor[sent.Count];
for (var i = 0; i < sent.Count; i++)
{
var form = _formemb[_train.Form[sent[i].Norm]];
form.RefCount++;
var pos = _posemb[_train.PosTag[sent[i].Pos]];
pos.RefCount++;
if (grad)
{
VariedParams.Add(form);
VariedParams.Add(pos);
}
x[i] = G.Concat(form, pos);
}
var t = _surface.Step(G, x);
for (var i = 0; i < sent.Count; i++)
{
sent[i].Repr = G.DropOut(t[i], 0.5f);
}
}
