protected override Delegate GetGetterCore(IChannel ch, IRow input, int iinfo, out Action disposer)
{
Contracts.AssertValueOrNull(ch);
Contracts.AssertValue(input);
Contracts.Assert(0 <= iinfo && iinfo < Infos.Length);
disposer = null;
int col = Infos[iinfo].Source;
var typeSrc = input.Schema.GetColumnType(col);
Contracts.Assert(RowCursorUtils.TestGetLabelGetter(typeSrc) == null);
return(RowCursorUtils.GetLabelGetter(input, col));
}
public override void InitializeNextPass(IRow row, RoleMappedSchema schema)
{
Contracts.Assert(PassNum < 1);
Contracts.AssertValue(schema.Label);
var score = schema.GetUniqueColumn(MetadataUtils.Const.ScoreValueKind.Score);
_labelGetter = RowCursorUtils.GetLabelGetter(row, schema.Label.Index);
_scoreGetter = row.GetGetter <TScore>(score.Index);
Contracts.AssertValue(_labelGetter);
Contracts.AssertValue(_scoreGetter);
if (schema.Weight != null)
{
_weightGetter = row.GetGetter <float>(schema.Weight.Index);
}
}
public override void InitializeNextPass(IRow row, RoleMappedSchema schema)
{
AssertValid(assertGetters: false);
Host.AssertValue(row);
Host.AssertValue(schema);
if (_calculateDbi)
{
Host.AssertValue(schema.Feature);
_featGetter = row.GetGetter <VBuffer <Single> >(schema.Feature.Index);
}
var score = schema.GetUniqueColumn(MetadataUtils.Const.ScoreValueKind.Score);
Host.Assert(score.Type.VectorSize == _scoresArr.Length);
_scoreGetter = row.GetGetter <VBuffer <Single> >(score.Index);
if (PassNum == 0)
{
if (schema.Label != null)
{
_labelGetter = RowCursorUtils.GetLabelGetter(row, schema.Label.Index);
}
else
{
_labelGetter = (ref Single value) => value = Single.NaN;
}
if (schema.Weight != null)
{
_weightGetter = row.GetGetter <Single>(schema.Weight.Index);
}
}
else
{
Host.Assert(PassNum == 1 && _calculateDbi);
UnweightedCounters.InitializeSecondPass(_clusterCentroids);
if (WeightedCounters != null)
{
WeightedCounters.InitializeSecondPass(_clusterCentroids);
}
}
AssertValid(assertGetters: true);
}
public override Delegate[] CreateGetters(IRow input, Func <int, bool> activeCols, out Action disposer)
{
Host.Assert(LabelIndex >= 0);
Host.Assert(ScoreIndex >= 0);
disposer = null;
long cachedPosition = -1;
Float label = 0;
var score = default(VBuffer <Float>);
var l1 = VBufferUtils.CreateDense <Double>(_scoreSize);
ValueGetter <Float> nanGetter = (ref Float value) => value = Single.NaN;
var labelGetter = activeCols(L1Col) || activeCols(L2Col) ? RowCursorUtils.GetLabelGetter(input, LabelIndex) : nanGetter;
ValueGetter <VBuffer <Float> > scoreGetter;
if (activeCols(L1Col) || activeCols(L2Col))
{
scoreGetter = input.GetGetter <VBuffer <Float> >(ScoreIndex);
}
else
{
scoreGetter = (ref VBuffer <Float> dst) => dst = default(VBuffer <Float>);
}
Action updateCacheIfNeeded =
() =>
{
if (cachedPosition != input.Position)
{
labelGetter(ref label);
scoreGetter(ref score);
var lab = (Double)label;
foreach (var s in score.Items(all: true))
{
l1.Values[s.Key] = Math.Abs(lab - s.Value);
}
cachedPosition = input.Position;
}
};
var getters = new Delegate[2];
if (activeCols(L1Col))
{
ValueGetter <VBuffer <Double> > l1Fn =
(ref VBuffer <Double> dst) =>
{
updateCacheIfNeeded();
l1.CopyTo(ref dst);
};
getters[L1Col] = l1Fn;
}
if (activeCols(L2Col))
{
VBufferUtils.PairManipulator <Double, Double> sqr =
(int slot, Double x, ref Double y) => y = x * x;
ValueGetter <VBuffer <Double> > l2Fn =
(ref VBuffer <Double> dst) =>
{
updateCacheIfNeeded();
dst = new VBuffer <Double>(_scoreSize, 0, dst.Values, dst.Indices);
VBufferUtils.ApplyWith(ref l1, ref dst, sqr);
};
getters[L2Col] = l2Fn;
}
return(getters);
}