public Transform(IHostEnvironment env, IDataView input, string labelCol, string scoreCol, string groupCol,
int truncationLevel, Double[] labelGains)
: base(env, input, labelCol, scoreCol, groupCol, RegistrationName)
{
Host.CheckParam(0 < truncationLevel, nameof(truncationLevel),
"Truncation level must be greater than 0");
Host.CheckValue(labelGains, nameof(labelGains));
_truncationLevel = truncationLevel;
_discountMap = RankingUtils.GetDiscountMap(_truncationLevel);
_labelGains = labelGains;
_bindings = new Bindings(Host, Source.Schema, true, LabelCol, ScoreCol, GroupCol, _truncationLevel);
}
protected override void UpdateState(RowCursorState state)
{
// Calculate the current group DCG, NDCG and MaxDcg.
RankingUtils.QueryMaxDcg(_labelGains, _truncationLevel, _discountMap, state.QueryLabels, state.QueryOutputs,
state.MaxDcgCur);
RankingUtils.QueryDcg(_labelGains, _truncationLevel, _discountMap, state.QueryLabels, state.QueryOutputs, state.DcgCur);
for (int t = 0; t < _truncationLevel; t++)
{
Double ndcg = state.MaxDcgCur[t] > 0 ? state.DcgCur[t] / state.MaxDcgCur[t] : 0;
state.NdcgCur[t] = ndcg;
}
state.QueryLabels.Clear();
state.QueryOutputs.Clear();
}
public void UpdateGroup(Single weight)
{
RankingUtils.QueryMaxDcg(_labelGains, TruncationLevel, _discountMap, _queryLabels, _queryOutputs, _groupMaxDcgCur);
if (_groupMaxDcg != null)
{
var maxDcg = new Double[TruncationLevel];
Array.Copy(_groupMaxDcgCur, maxDcg, TruncationLevel);
_groupMaxDcg.Add(maxDcg);
}
RankingUtils.QueryDcg(_labelGains, TruncationLevel, _discountMap, _queryLabels, _queryOutputs, _groupDcgCur);
if (_groupDcg != null)
{
var groupDcg = new Double[TruncationLevel];
Array.Copy(_groupDcgCur, groupDcg, TruncationLevel);
_groupDcg.Add(groupDcg);
}
var groupNdcg = new Double[TruncationLevel];
for (int t = 0; t < TruncationLevel; t++)
{
Double ndcg = _groupMaxDcgCur[t] > 0 ? _groupDcgCur[t] / _groupMaxDcgCur[t] : 0;
_sumNdcgAtN[t] += ndcg * weight;
_sumDcgAtN[t] += _groupDcgCur[t] * weight;
groupNdcg[t] = ndcg;
}
_sumWeights += weight;
if (_groupNdcg != null)
{
_groupNdcg.Add(groupNdcg);
}
_queryLabels.Clear();
_queryOutputs.Clear();
}
public Counters(Double[] labelGains, int truncationLevel, bool groupSummary)
{
Contracts.Assert(truncationLevel > 0);
Contracts.AssertValue(labelGains);
TruncationLevel = truncationLevel;
_discountMap = RankingUtils.GetDiscountMap(truncationLevel);
_sumDcgAtN = new Double[TruncationLevel];
_sumNdcgAtN = new Double[TruncationLevel];
_groupDcgCur = new Double[TruncationLevel];
_groupMaxDcgCur = new Double[TruncationLevel];
if (groupSummary)
{
_groupNdcg = new List <Double[]>();
_groupDcg = new List <Double[]>();
_groupMaxDcg = new List <Double[]>();
}
_queryLabels = new List <short>();
_queryOutputs = new List <Single>();
_labelGains = labelGains;
}
