private static void WriteOutput(AggregationOptions opts, DateTime currentMinDate, List <List <double> > sums)
{
List <string> fields = new List <string> {
opts.AggregationPeriod.DateText(currentMinDate)
};
fields.AddRange(sums.Select(list => list.Any() ? opts.AggregationFunc(list).ToString("f") : string.Empty));
Console.Write(string.Join(opts.Delimiter ?? "\t", fields) + "\n");
}
