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Anonymous's avatar
Anonymous
Not applicable
5 years ago
Solved

Delta values

Hi,   How would I calculate Delta-values derived from a Date in combination with ID: Date ID Values Delta-values DD-MM-YYYY  12:00 1 88   DD-MM-YYYY  12:00 2 23   DD-MM-YYYY  ...
Need Help
  • Anonymous's avatar
    Anonymous
    5 years ago

    Hi  Anonymous ,

    Here are the steps you can follow：

    1. Increase the index through power query

    2. Create calculcated column.

    Delta-values =
var _lastindex=
CALCULATE(MAX('Table'[Index]),FILTER(ALL('Table'),[Metern]=EARLIER([Metern])&&[Index]<EARLIER([Index])))

var _lastdata=
CALCULATE(SUM('Table'[Data]),FILTER('Table',[Index]=_lastindex))

return IF(_lastindex=BLANK(),BLANK(),[Data]-_lastdata)

    3. Result.

    You can downloaded PBIX file from here.

     

    Best Regards,

    Liu Yang

    If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

Anonymous's avatar
Anonymous
Not applicable
5 years ago

To fact that you can do something does not mean you should. Such data transformations are best done (and easy!) in Power Query. DAX should be used to create calculated columns only as the very, very, very last resort. There are many reasons behind this, two of them being poor compression and model bloat if done through DAX. Please use Power Query - the right tool for the job.

Anonymous's avatar
Anonymous
Not applicable
5 years ago

Daxer,

That all makes sense,

However, I would still need the DAX code for it,

 

Any input for the DAX code highly appreciated!

  • Anonymous's avatar
    Anonymous
    Not applicable
    5 years ago

    No, you don't need DAX. You need M - the language of Power Query. That's the whole point. DAX is for data analysis. M is for data munging.

    • Anonymous's avatar
      Anonymous
      Not applicable
      5 years ago

      Sorry - so Power Query it is.. 

      Still need the a working code though!

      • Anonymous's avatar
        Anonymous
        Not applicable
        5 years ago

         

        let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("hY9BCsAgDAS/UnK2mGytFL8i/v8btdCi1gUhOY3ZdXIWKHRXq7MZkmodcWJ1IcX9+dnxY+IhoeM28TjkB5L/cdD71g/6v9YPmh+H/GvkWPhj4Q/ur/Bq/nnF/XvO/Ec++/ec+fP+17/c", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Datetime = _t, ID = _t, Value = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Datetime", type datetime}, {"ID", Int64.Type}, {"Value", Int64.Type}}),
    #"Sorted Rows" = Table.Sort(#"Changed Type",{{"ID", Order.Ascending}, {"Datetime", Order.Ascending}}),
    #"Added Index" = Table.AddIndexColumn(#"Sorted Rows", "Index", 1, 1, Int64.Type),
    #"Reordered Columns" = Table.ReorderColumns(#"Added Index",{"Index", "Datetime", "ID", "Value"}),
    #"Added Custom" = Table.AddColumn(#"Reordered Columns", 
        "ValueBefore", 
        each Table.SelectRows(
                #"Reordered Columns", 
                (r) => r[ID] = [ID] and [Index] = r[Index] + 1)
    ),
    #"Expanded ValueBefore" = Table.ExpandTableColumn(#"Added Custom", "ValueBefore", {"Value"}, {"Value.1"}),
    #"Renamed Columns" = Table.RenameColumns(#"Expanded ValueBefore",{{"Value.1", "ValueBefore"}}),
    #"Added Custom1" = Table.AddColumn(#"Renamed Columns", "Delta", each [Value] - [ValueBefore]),
    #"Removed Columns" = Table.RemoveColumns(#"Added Custom1",{"Value", "ValueBefore", "Index"})
in
    #"Removed Columns"

         

        Here's the M code. Paste it into the Advanced Editor in Power Query and you'll see step-by-step how this is done. Then use it accordingly.