public XArray Remap(XArray source, ref int[] remapArray)
{
// See if we have the remapping cached already
ArraySelector cachedMapping;
if (_cachedRemappings.TryGetValue(source.Selector, out cachedMapping))
{
return(source.Reselect(cachedMapping));
}
// Convert the BitVector to indices if we haven't yet (deferred to first column wanting values)
if (!_indicesFound)
{
_indicesFound = true;
Allocator.AllocateToSize(ref _indices, _count);
int countFound = _vector.Page(_indices, ref _nextVectorIndex, _count);
if (countFound != _count)
{
throw new InvalidOperationException($"RowRemapper found {countFound:n0} rows when {_count:n0} expected paging in Vector with {_vector.Count:n0} total matches up to index {_nextVectorIndex:n0}.");
}
}
// Remap the outer selector
XArray remapped = source.Select(ArraySelector.Map(_indices, _count), ref remapArray);
// Cache the remapping
_cachedRemappings[source.Selector] = remapped.Selector;
return(remapped);
}
private void PostSortAndFilter(XArray groups, XArray counts, int totalRowCount, bool wasAllRows)
{
int[] finalIndices = new int[groups.Count];
int[] finalCounts = new int[groups.Count];
int groupCount = 0;
// Filter to counts over the minimum percentage threshold
int[] countsArray = (int[])counts.Array;
if (countsArray != null)
{
int threshold = (int)(totalRowCount * MinimumPercentageToReport);
for (int i = 0; i < groups.Count; ++i)
{
int count = countsArray[counts.Index(i)];
if (count >= threshold)
{
finalIndices[groupCount] = i;
finalCounts[groupCount] = count;
groupCount++;
}
}
}
// Sort the values by count descending
Array.Sort <int, int>(finalCounts, finalIndices, 0, groupCount, new ReverseComparer());
// Limit to the top N if needed
if (groupCount > MaximumCountToReturn)
{
groupCount = MaximumCountToReturn;
}
// Set the distinct count (now that it's known)
_distinctCount = groupCount;
// Set the output values
int[] groupsRemap = null;
XArray finalCountsX = XArray.All(finalCounts, groupCount);
_columns[0].SetValues(groups.Select(ArraySelector.Map(finalIndices, groupCount), ref groupsRemap));
_columns[1].SetValues(finalCountsX);
if (wasAllRows)
{
_columns[2].SetValues(PercentageAggregator.ToPercentageStrings(finalCountsX, totalRowCount, PercentageAggregator.TwoSigFigs));
}
else
{
_columns[2].SetValues(PercentageAggregator.ToPercentageStrings(finalCountsX, totalRowCount, PercentageAggregator.WholePercentage));
}
}
public Func <XArray> CurrentGetter()
{
return(() => _allValues.Select(_currentSelector, ref _remapArray));
}
public XArray Read(ArraySelector selector)
{
return(_column.Select(selector, ref _remapArray));
}
// Return an XArray with a slice of the rows only
public static XArray Slice(XArray values, int startIndexInclusive, int endIndexExclusive)
{
int[] remapArray = null;
return(values.Select(values.Selector.Slice(startIndexInclusive, endIndexExclusive), ref remapArray));
}
