internal static ValueGetter <VBuffer <Single> > GetLabelGetter(SlotCursor cursor)
{
var type = cursor.GetSlotType().ItemType;
if (type == NumberDataViewType.Single)
{
return(cursor.GetGetter <Single>());
}
if (type == NumberDataViewType.Double || type is BooleanDataViewType)
{
return(GetVecGetterAs <Single>(NumberDataViewType.Single, cursor));
}
if (!(type is KeyType keyType))
{
throw Contracts.Except("Only floating point number, boolean, and key type values can be used as label.");
}
Contracts.Assert(TestGetLabelGetter(type) == null);
ulong keyMax = (ulong)keyType.Count;
if (keyMax == 0)
{
keyMax = ulong.MaxValue;
}
var getSrc = RowCursorUtils.GetVecGetterAs <ulong>(NumberDataViewType.UInt64, cursor);
VBuffer <ulong> src = default(VBuffer <ulong>);
return
((ref VBuffer <Single> dst) =>
{
getSrc(ref src);
// Unfortunately defaults in one to not translate to defaults of the other,
// so this will not be sparsity preserving. Assume a dense output.
var editor = VBufferEditor.Create(ref dst, src.Length);
foreach (var kv in src.Items(all: true))
{
if (0 < kv.Value && kv.Value <= keyMax)
{
editor.Values[kv.Key] = kv.Value - 1;
}
else
{
editor.Values[kv.Key] = Single.NaN;
}
}
dst = editor.Commit();
});
}
internal override void InitializeNextPass(Row row, RoleMappedSchema schema)
{
Contracts.Assert(PassNum < 1);
Contracts.Assert(schema.Label.HasValue);
var score = schema.GetUniqueColumn(MetadataUtils.Const.ScoreValueKind.Score);
_labelGetter = RowCursorUtils.GetVecGetterAs <Float>(NumberType.Float, row, schema.Label.Value.Index);
_scoreGetter = row.GetGetter <VBuffer <Float> >(score.Index);
Contracts.AssertValue(_labelGetter);
Contracts.AssertValue(_scoreGetter);
if (schema.Weight.HasValue)
{
_weightGetter = row.GetGetter <Float>(schema.Weight.Value.Index);
}
}
private protected override Delegate[] CreateGettersCore(Row input, Func <int, bool> activeCols, out Action disposer)
{
Host.Assert(LabelIndex >= 0);
Host.Assert(ScoreIndex >= 0);
disposer = null;
long cachedPosition = -1;
var label = default(VBuffer <Float>);
var score = default(VBuffer <Float>);
ValueGetter <VBuffer <Float> > nullGetter = (ref VBuffer <Float> vec) => vec = default(VBuffer <Float>);
var labelGetter = activeCols(LabelOutput) || activeCols(L1Output) || activeCols(L2Output) || activeCols(DistCol)
? RowCursorUtils.GetVecGetterAs <Float>(NumberType.Float, input, LabelIndex)
: nullGetter;
var scoreGetter = activeCols(ScoreOutput) || activeCols(L1Output) || activeCols(L2Output) || activeCols(DistCol)
? input.GetGetter <VBuffer <Float> >(ScoreIndex)
: nullGetter;
Action updateCacheIfNeeded =
() =>
{
if (cachedPosition != input.Position)
{
labelGetter(ref label);
scoreGetter(ref score);
cachedPosition = input.Position;
}
};
var getters = new Delegate[5];
if (activeCols(LabelOutput))
{
ValueGetter <VBuffer <Float> > labelFn =
(ref VBuffer <Float> dst) =>
{
updateCacheIfNeeded();
label.CopyTo(ref dst);
};
getters[LabelOutput] = labelFn;
}
if (activeCols(ScoreOutput))
{
ValueGetter <VBuffer <Float> > scoreFn =
(ref VBuffer <Float> dst) =>
{
updateCacheIfNeeded();
score.CopyTo(ref dst);
};
getters[ScoreOutput] = scoreFn;
}
if (activeCols(L1Output))
{
ValueGetter <double> l1Fn =
(ref double dst) =>
{
updateCacheIfNeeded();
dst = VectorUtils.L1Distance(in label, in score);
};
getters[L1Output] = l1Fn;
}