/// <summary>
/// Create Value object from dense input as batch of sequences data with sequenceStartFlags.
/// </summary>
/// <typeparam name="T">data type</typeparam>
/// <param name="sampleShape">data shape</param>
/// <param name="sequences">data sequence</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>(NDShape sampleShape,
IEnumerable <IEnumerable <T> > sequences,
IEnumerable <bool> sequenceStartFlags,
DeviceDescriptor device,
bool readOnly = false)
{
var seqFlags = Helper.AsBoolVector(sequenceStartFlags);
if (typeof(T).Equals(typeof(float)))
{
var inputAsSequencesVector = new FloatVectorVector();
foreach (var seq in sequences)
{
var seqVector = Helper.AsFloatVector(seq);
// The seqVector is copied when adding to inputAsSequencesVector.
inputAsSequencesVector.Add(seqVector);
}
return(Value._CreateDenseFloat(sampleShape, inputAsSequencesVector, seqFlags, device, readOnly));
}
else if (typeof(T).Equals(typeof(double)))
{
var inputAsSequencesVector = new DoubleVectorVector();
foreach (var seq in sequences)
{
var seqVector = Helper.AsDoubleVector(seq);
inputAsSequencesVector.Add(seqVector);
}
return(Value._CreateDenseDouble(sampleShape, inputAsSequencesVector, 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 IList<T>, contains a variable number of samples.
/// Each sample consits of a fixed number of elements with type of 'T'. The number of elements is determined by the variable shape.
/// The number of samples = (the count of elements in IList<T>)/(the count of elements of the sample)
/// The shape of the variable should match the shape of the Value object.
/// </summary>
/// <typeparam name="T">data type</typeparam>
/// <param name="outputVariable">the source variable</param>
/// <returns></returns>
public IList <IList <T> > GetDenseData <T>(Variable outputVariable)
{
var sequences = new List <IList <T> >();
if (typeof(T).Equals(typeof(float)))
{
if (_GetDataType() != DataType.Float)
{
throw new ArgumentException("The value type does not match the list type.");
}
var seqVec = new FloatVectorVector();
_CopyVariableValueToFloat(outputVariable, seqVec);
foreach (var seq in seqVec)
{
var seqList = seq as IList <T>;
if (seqList == null)
{
throw new TypeAccessException("Cannot convert to the value type.");
}
// It is required to create a new List from seq, since seq is dependent on the life cycle of seqVec.
sequences.Add(new List <T>(seqList));
}
}
else if (typeof(T).Equals(typeof(double)))
{
if (_GetDataType() != DataType.Double)
{
throw new ArgumentException("The value type does not match the list type.");
}
var seqVec = new DoubleVectorVector();
_CopyVariableValueToDouble(outputVariable, seqVec);
foreach (var seq in seqVec)
{
var seqList = seq as IList <T>;
if (seqList == null)
{
throw new TypeAccessException("Cannot convert to the value type.");
}
// It is required to create a new List from seq, since seq is dependent on the life cycle of seqVec.
sequences.Add(new List <T>(seqList));
}
}
else
{
throw new ArgumentException("The value type does not match the list type.");
}
return(sequences);
}
public void CopyVariableValueTo <T>(Variable outputVariable, List <List <T> > sequences)
{
sequences.Clear();
if (typeof(T).Equals(typeof(float)))
{
if (_GetDataType() != DataType.Float)
{
throw new ArgumentException("The value type does not match the list type.");
}
var seqVec = new FloatVectorVector();
_CopyVariableValueToFloat(outputVariable, seqVec);
foreach (var seq in seqVec)
{
var seqList = seq as IList <T>;
if (seqList == null)
{
throw new TypeAccessException("Cannot convert to the value type.");
}
sequences.Add(new List <T>(seqList));
}
}
else if (typeof(T).Equals(typeof(double)))
{
if (_GetDataType() != DataType.Double)
{
throw new ArgumentException("The value type does not match the list type.");
}
var seqVec = new DoubleVectorVector();
_CopyVariableValueToDouble(outputVariable, seqVec);
foreach (var seq in seqVec)
{
var seqList = seq as IList <T>;
if (seqList == null)
{
throw new TypeAccessException("Cannot convert to the value type.");
}
sequences.Add(new List <T>(seqList));
}
}
else
{
throw new ArgumentException("The value type does not match the list type.");
}
}
// Create Value based on dense input
// Todo: could this be a extension to Value class??
// Todo: use Variable instead of varName. VarName as extension method
// Todo: List can have maximal 2^31-1, enough? Otherwise need to go to array which supports 64bit size
public Value CreateValue <T>(string varName, List <List <T> > sequences, DeviceDescriptor computeDevice)
{
var variable = getVariableByName(varName);
var dim = variable.Shape.TotalSize;
if (typeof(T).Equals(typeof(float)))
{
var inputSeqVector = new FloatVectorVector();
foreach (var seq in sequences)
{
if (seq.Count() % dim != 0)
{
throw new InvalidDataException("the number of data in sequences does not match the input dimension");
}
var samples = new FloatVector(seq);
inputSeqVector.Add(samples);
}
var inputValue = Value.CreateDenseFloat(variable.Shape, inputSeqVector, computeDevice);
return(inputValue);
}
else if (typeof(T).Equals(typeof(double)))
{
var inputSeqVector = new DoubleVectorVector();
foreach (var seq in sequences)
{
if (seq.Count() % dim != 0)
{
throw new InvalidDataException("the number of data in sequences does not match the input dimension");
}
var samples = new DoubleVector(seq);
inputSeqVector.Add(samples);
}
var inputValue = Value.CreateDenseDouble(variable.Shape, inputSeqVector, computeDevice);
return(inputValue);
}
else
{
throw new InvalidDataException("The data type " + typeof(T).ToString() + " is not supported. Only float or double is supported by CNTK.");
}
}