public ExpressionSampler(string name, Variable expression, Variable inputVariable = null, int minibatchSize = 1, Value initialValue = null, int iterationsPerEpoch = int.MaxValue)
{
Name = name;
Expression = expression;
InputVariable = inputVariable;
MinibatchSize = minibatchSize;
_initialValue = initialValue;
if (initialValue != null)
{
PrevValue = initialValue;
}
else
{
if (InputVariable != null)
{
var shape = expression.Shape;
var initialBuffer = new float[shape.TotalSize * minibatchSize];
var dims = new int[shape.Rank + 1];
shape.Dimensions.CopyTo(dims, 0);
dims[shape.Rank] = minibatchSize;
PrevValue = new Value(NDArrayViewMethods.SafeCreate(dims, initialBuffer, DeviceDescriptor.UseDefaultDevice()));
}
}
IterationsPerEpoch = iterationsPerEpoch;
Iterations = 0;
}
public static CNTK.NDArrayView ArrayToNDArrayView(float[] data, int[] dimensions, CNTK.DeviceDescriptor device = null)
{
if (device == null)
{
device = CNTK.DeviceDescriptor.UseDefaultDevice();
}
return(NDArrayViewMethods.SafeCreate(dimensions, data, device));
}
protected override void EndProcessing()
{
Constant result;
if (InitialValue.Length == 1)
{
result = Constant.Scalar(DataType, InitialValue[0]);
}
else
{
if (Dimensions == null)
{
Dimensions = new int[] { InitialValue.Length }
}
;
var array = NDArrayViewMethods.SafeCreate(Dimensions, InitialValue, Device);
result = new Constant(array, Name);
}
WriteObject(new WrappedVariable(result));
}
}