/// <summary>
/// Create Value object from OneHotVector input as batch of sequences data with sequenceStratFlags, for 1D tensor only.
/// </summary>
/// <typeparam name="T">data type</typeparam>
/// <param name="dimension">data dimension</param>
/// <param name="sequences">data sequences</param>
/// <param name="sequenceStartFlag">true indicates that it is a new sequence.
/// false means a continuation of a previous sequence.</param>
/// <param name="device">device</param>
/// <param name="readOnly">whether it a readonly value</param>
/// <returns></returns>
public static Value Create <T>(int dimension,
IEnumerable <IEnumerable <int> > sequences,
IEnumerable <bool> sequenceStartFlags,
DeviceDescriptor device,
bool readOnly = false)
{
var seqFlags = Helper.AsBoolVector(sequenceStartFlags);
var inputSeqVector = new SizeTVectorVector();
foreach (var seq in sequences)
{
var s = Helper.AsSizeTVector(seq);
inputSeqVector.Add(s);
}
if (typeof(T).Equals(typeof(float)))
{
return(Value._CreateOneHotFloat((uint)dimension, inputSeqVector, seqFlags, device, readOnly));
}
else if (typeof(T).Equals(typeof(double)))
{
return(Value._CreateOneHotDouble((uint)dimension, inputSeqVector, seqFlags, device, readOnly));
}
else
{
throw new ArgumentException("The data type " + typeof(T).ToString() + " is not supported. Only float or double is supported by CNTK.");
}
}
/// <summary>
/// Return the data of the Value object as a list of sequences with variable length.
/// This method returns an IList<IList<T>>. Each element of the outer list represents a sequence.
/// Each sequence, represented by List<int>, contains a variable number of samples.
/// Each sample is represented by an index of the OneHot vector. The size of the OneHot vector should match that defined in the variable.
/// The number of samples = the count of elements in List<int>.
/// </summary>
/// <param name="outputVariable">the source variable</param>
/// <returns></returns>
public IList <IList <int> > GetOneHotData(Variable outputVariable)
{
var sequences = new List <IList <int> >();
var seqVec = new SizeTVectorVector();
_CopyVariableValueTo(outputVariable, seqVec);
foreach (var seq in seqVec)
{
var seqList = new List <int>(seq.Count);
foreach (var element in seq)
{
seqList.Add((int)element);
}
sequences.Add(seqList);
}
return(sequences);
}
public void CopyVariableValueTo(Variable outputVariable, List <List <int> > sequences)
{
var seqVec = new SizeTVectorVector();
_CopyVariableValueTo(outputVariable, seqVec);
sequences.Clear();
foreach (var seq in seqVec)
{
var seqList = new List <int>(seq.Count);
foreach (var element in seq)
{
seqList.Add((int)element);
}
sequences.Add(seqList);
}
return;
}
//
// Copy the data of the Value object into the buffer provided by 'sequences'.
// The 'sequences' is a list of sequences with variable length.
// The number of items contained in the outer list of 'sequences' is the number of sequences in the Value object.
// Each element of the outer list represents a sequence.
// Each sequence, represented by List<uint>, contains a variable number of samples.
// Each sample is represented by an index of the OneHot vector. The size of the OneHot vector should match that defined in the variable.
// The number of samples = the count of elements in List<uint>.
//
public static void CopyVariableValueTo(this Value value, Variable sampleVariable, List <List <uint> > sequences)
{
if (sampleVariable.Shape[0] != sampleVariable.Shape.TotalSize)
{
throw new ArgumentException("The sample variable's leading axis dimensionality must equal to the total size of the shape for sparse data");
}
var seqVec = new SizeTVectorVector();
value.CopyVariableValueTo(sampleVariable, seqVec);
sequences.Clear();
foreach (var seq in seqVec)
{
sequences.Add(new List <uint>(seq));
}
return;
}
