grouping

问题 In a data frame, I have a column with Y and N values. This data frame also has an id column. I would like to create two columns, one with the total Y count and another with the total N count for each id. I tried doing this procedure with the dplyr summarise function group_by(id) %>% summarise(total_not = count(column_y_e_n == "N"), total_yes = count(column_y_e_n == "Y") but objected to the error message Error in summarise_impl(.data, dots) Any sugestion? 回答1: Slight variation on original

来源： https://stackoverflow.com/questions/64527882/apache-flink-output-to-csv-file-for-each-groupeddataset

来源： https://stackoverflow.com/questions/50264717/get-all-possible-combination-of-items-in-array-without-duplicate-groups-in-swift

来源： https://stackoverflow.com/questions/64007253/estimate-total-sum-of-joined-tables

来源： https://stackoverflow.com/questions/64007253/estimate-total-sum-of-joined-tables

来源： https://stackoverflow.com/questions/64425393/group-list-of-complex-object-using-java-stream

来源： https://stackoverflow.com/questions/64425393/group-list-of-complex-object-using-java-stream

来源： https://stackoverflow.com/questions/6785085/linq-or-pseudocode-to-group-items-by-proximity

问题 I want to GroupBy multiple objects in a list of records and not simply multiple values. I am having trouble getting grouping to work with reference type objects. I have a collection of objects that contain Room, Type, and DateTime. Room, Type, and DateTime all have properties associated with them. I've already added the IEquateable interface to the room and the type thinking that would be enough to with with group by. var groups = collection .Where(g => g.Stage == InventoryStage.StageA)

问题 I would like a third column "items" with the values that are grouped. var dic = new Dictionary<string, int>(); dic.Add("a", 1); dic.Add("b", 1); dic.Add("c", 2); dic.Add("d", 3); var dCounts = (from i in dic group i by i.Value into g select new { g.Key, count = g.Count()}); var a = dCounts.Where(c => c.count>1 ); dCounts.Dump(); a.Dump(); This code results in: Key Count 1 2 2 1 3 1 I would like these results: Key Count Items 1 2 a, b 2 1 c 3 1 d 回答1: var dCounts = (from i in dic group i by i