//------------------------------------------------------------------------------------------------ public static Frame<string, string> sortFrameByNaturalOrder(Frame<string, string> input, List<string>contractSortOrder ) //------------------------------------------------------------------------------------------------ { var series = input.GetColumn<string>("ticker").SelectValues(s => futuresSortValue(s, contractSortOrder)); input.AddColumn("SortValue",series); input = input.SortRows("SortValue"); return input; }