public virtual void Sumup(SumupInputData input, FeatureHistogram histogram)
{
Contracts.Assert((input.Weights == null) == (histogram.SumWeightsByBin == null));
if (histogram.SumWeightsByBin != null)
{
SumupWeighted(input, histogram);
return;
}
IIntArrayForwardIndexer indexer = GetIndexer();
for (int i = 0; i < input.TotalCount; i++)
{
int featureBin = input.DocIndices == null ? indexer[i] : indexer[input.DocIndices[i]];
if (featureBin < 0 ||
featureBin >= histogram.SumTargetsByBin.Length ||
featureBin >= histogram.NumFeatureValues)
{
throw Contracts.Except("Feature bin {0} is invalid", featureBin);
}
histogram.SumTargetsByBin[featureBin] += input.Outputs[i];
++histogram.CountByBin[featureBin];
}
}
private unsafe void SumupRoot(SumupInputData input, FeatureHistogram histogram)
{
fixed(FloatType *pOutputsFixed = input.Outputs)
fixed(FloatType * pSumTargetsFixed = histogram.SumTargetsByBin)
fixed(double *pWeightsFixed = input.Weights)
fixed(double *pSumWeightsFixed = histogram.SumWeightsByBin)
{
FloatType *pOutputs = pOutputsFixed;
double * pWeights = pWeightsFixed;
for (int i = 0; i < _values.Length; i++)
{
int featureBin = _values[i];
//FloatType* pSumTargets = pSumTargetsFixed + featureBin;
FloatType subsum = pSumTargetsFixed[featureBin];
for (int j = 0; j < _deltas[i]; ++j)
{
subsum += pOutputs[j];
}
pSumTargetsFixed[featureBin] = subsum;
if (pWeightsFixed != null)
{
double subweightsum = pSumWeightsFixed[featureBin];
for (int j = 0; j < _deltas[i]; ++j)
{
subweightsum += pWeights[j];
}
pSumWeightsFixed[featureBin] = subweightsum;
pWeights += _deltas[i];
}
pOutputs += _deltas[i];
histogram.CountByBin[featureBin] += _deltas[i];
}
}
}
private unsafe void SumupLeafWeighted(SumupInputData input, FeatureHistogram histogram)
{
Contracts.Assert(histogram.SumWeightsByBin != null);
Contracts.Assert(input.Weights != null);
int iDocIndices = 0;
int iSparse = 0;
int totalCount = 0;
FloatType totalOutput = 0;
double totalWeights = 0;
int currentPos = _deltas.Length > 0 ? _deltas[iSparse] : _length;
fixed(int *pDocIndices = input.DocIndices)
fixed(byte *pDeltas = _deltas)
fixed(FloatType * pOutputs = input.Outputs)
fixed(double *pWeights = input.Weights)
{
while (true)
{
if (currentPos < pDocIndices[iDocIndices])
{
if (++iSparse >= _deltas.Length)
{
break;
}
currentPos += pDeltas[iSparse];
}
else if (currentPos > pDocIndices[iDocIndices])
{
if (++iDocIndices >= input.TotalCount)
{
break;
}
}
else
{
// a nonzero entry matched one of the docs in the leaf, add it to the histogram
int featureBin = _values[iSparse];
FloatType output = pOutputs[iDocIndices];
histogram.SumTargetsByBin[featureBin] += output;
totalOutput += output;
double weights = pWeights[iDocIndices];
histogram.SumWeightsByBin[featureBin] += weights;
totalWeights += weights;
++histogram.CountByBin[featureBin];
totalCount++;
if (++iSparse >= _deltas.Length)
{
break;
}
if (pDeltas[iSparse] > 0)
{
currentPos += pDeltas[iSparse];
if (++iDocIndices >= input.TotalCount)
{
break;
}
}
}
}
}
// Fixup the zeros. There were some zero items already placed in the zero-th entry, just add the remainder
histogram.SumTargetsByBin[0] += (FloatType)(input.SumTargets - totalOutput);
histogram.SumWeightsByBin[0] += (FloatType)(input.SumWeights - totalWeights);
histogram.CountByBin[0] += input.TotalCount - totalCount;
}
// Fixing the arrays and using unsafe accesses may give a slight speedup, but it is hard to tell.
// OPTIMIZE: Another two methods would be doing binary search or using a hashtable -- binary search
// when there are very few docs in the leaf
private unsafe void SumupLeaf(SumupInputData input, FeatureHistogram histogram)
{
if (histogram.SumWeightsByBin != null)
{
SumupLeafWeighted(input, histogram);
return;
}
int iDocIndices = 0;
int iSparse = 0;
int totalCount = 0;
FloatType totalOutput = 0;
int currentPos = _deltas.Length > 0 ? _deltas[iSparse] : _length;
fixed(int *pDocIndices = input.DocIndices)
fixed(byte *pDeltas = _deltas)
fixed(FloatType * pOutputs = input.Outputs)
{
for (; ;)
{
if (currentPos < pDocIndices[iDocIndices])
{
if (++iSparse >= _deltas.Length)
{
break;
}
currentPos += pDeltas[iSparse];
}
else if (currentPos > pDocIndices[iDocIndices])
{
if (++iDocIndices >= input.TotalCount)
{
break;
}
}
else
{
// A nonzero entry matched one of the docs in the leaf, add it to the histogram.
int featureBin = _values[iSparse];
FloatType output = pOutputs[iDocIndices];
histogram.SumTargetsByBin[featureBin] += output;
totalOutput += output;
++histogram.CountByBin[featureBin];
totalCount++;
if (++iSparse >= _deltas.Length)
{
break;
}
// Note that if the delta is 0, we will "stay" on this document, thus
// allowing the sumup to work to accumulate multiple bins per document.
if (pDeltas[iSparse] > 0)
{
currentPos += pDeltas[iSparse];
if (++iDocIndices >= input.TotalCount)
{
break;
}
}
}
}
}
// Fixup the zeros. There were some zero items already placed in the zero-th entry, just add the remainder
histogram.SumTargetsByBin[0] += (FloatType)(input.SumTargets - totalOutput);
histogram.CountByBin[0] += input.TotalCount - totalCount;
}