public SharedFormulaGroup(SharedFormulaRecord sfr, CellReference firstCell) { if (!sfr.IsInRange(firstCell.Row, firstCell.Col)) { throw new ArgumentException("First formula cell " + firstCell.FormatAsString() + " is not shared formula range " + sfr.Range.ToString() + "."); } _sfr = sfr; _firstCell = firstCell; int width = sfr.LastColumn - sfr.FirstColumn + 1; int height = sfr.LastRow - sfr.FirstRow + 1; _frAggs = new FormulaRecordAggregate[width * height]; _numberOfFormulas = 0; }