public static ValueGetter <VBuffer <Single> > GetLabelGetter(SlotCursor cursor)
{
var type = cursor.GetSlotType().ItemType;
if (type == NumberType.R4)
{
return(cursor.GetGetter <Single>());
}
if (type == NumberType.R8 || type.IsBool)
{
return(GetVecGetterAs <Single>(NumberType.R4, cursor));
}
Contracts.Check(type.IsKey, "Only floating point number, boolean, and key type values can be used as label.");
Contracts.Assert(TestGetLabelGetter(type) == null);
ulong keyMax = (ulong)type.KeyCount;
if (keyMax == 0)
{
keyMax = ulong.MaxValue;
}
var getSrc = RowCursorUtils.GetVecGetterAs <ulong>(NumberType.U8, 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();
});
}
