private function getPivotTableDefaultRowFromColumnSummary($columnSet, $othersRowLabel)
{
// sort columns by sum (to ensure deterministic ordering)
arsort($columnSet);
// limit columns if necessary (adding aggregate Others column at end)
if ($this->pivotByColumnLimit > 0 && count($columnSet) > $this->pivotByColumnLimit) {
$columnSet = array_slice($columnSet, 0, $this->pivotByColumnLimit - 1, $preserveKeys = true);
$columnSet[$othersRowLabel] = 0;
}
// remove column sums from array so it can be used as a default row
$columnSet = array_map(function () {
return false;
}, $columnSet);
// make sure label column is first
$columnSet = array('label' => false) + $columnSet;
return $columnSet;
}