Changes by Date and Items

[Anonymous]

hi all, i have a table in power bi desktop as in the following, i need to calculate the daily changes for each item starting from the minimum value whcih is already on the first date,new dates are added every day with new values (accumulated)

Name	Date	Cumulative Value
item1	date1	1
item2	date1	6
item3	date1	9
item1	date2	6
item2	date2	12
item3	date2	16
item1	date3	11
item2	date3	26
item3	date3	28

[v-yingjl · Accepted solution]

Hi @Anonymous ,

You can try this query:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WyixJzTVU0lEyMjAy1DfRBzENlWJ1IBJGqBJmcAljVAlLuASSUUYoOoxQJQyNsJkFljHDZhhIkSFWh4G1Y3UZmGmhFBsLAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Name = _t, Date = _t, #"Cumulative Value" = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Name", type text}, {"Date", type date}, {"Cumulative Value", Int64.Type}}),
    #"Grouped Rows" = Table.Group(#"Changed Type", {"Name"}, {{"Data", each let tab=Table.AddIndexColumn(_,"Index",1,1,Int64.Type) in Table.AddColumn(tab,"New",(x)=>try Table.Max( Table.SelectRows(tab,(y)=>y[Index]=x[Index]-1),"Index")[Cumulative Value] otherwise (x)[Cumulative Value] ), type table [Name=nullable text, Date=nullable date]}}),
    #"Added Custom" = Table.AddColumn(#"Grouped Rows", "New Data", each Table.AddColumn([Data],"Diff", each [Cumulative Value] - [New])),
    #"Removed Columns" = Table.RemoveColumns(#"Added Custom",{"Data"}),
    #"Expanded New Data" = Table.ExpandTableColumn(#"Removed Columns", "New Data", {"Date", "Cumulative Value", "Diff"}, {"New Data.Date", "New Data.Cumulative Value", "New Data.Diff"}),
    #"Sorted Rows" = Table.Sort(#"Expanded New Data",{{"New Data.Date", Order.Ascending}, {"Name", Order.Ascending}}),
    #"Renamed Columns" = Table.RenameColumns(#"Sorted Rows",{{"New Data.Date", "Date"}, {"New Data.Cumulative Value", "Cumulative Value"}, {"New Data.Diff", "Diff"}}),
    #"Changed Type1" = Table.TransformColumnTypes(#"Renamed Columns",{{"Date", type date}, {"Cumulative Value", Int64.Type}, {"Diff", Int64.Type}})
in
    #"Changed Type1"

Best Regards,
Community Support Team _ Yingjie Li
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

[artemus]

You can use the following formula, just replace MyTable with the name of the previous step:

= Table.FromColumns(Table.ToColumns(MyTable) & {List.Accumulate(MyTable[Cumulative Value], [List = {}, Prev = 0], (current, next) => [List = current[List] & {next - current[Prev]}, Prev = next - current[Prev]])[List]}, Table.ColumnNames(MyTable) & {"DoD"})