RSI - Relative Strength Index - formula to PowerPivot

Question

Hello All
We´re trying to add the RSI ( Relative Strength Index ) formula to  monthly data within PowerPivot.
Most of the work is done in the sample below:
Relative Strength Index Sample
But it complicates quickly when recursion is needed.
We already have the datamodel with the calendar, some sample data and the first working formulas in the sample.
The rest of the needed formulas are in the excel spreadsheet, but we need them within PowerPivot.
Can you please take a look and help?

Answer 1

Awesome :)
I´m having a hard time changing the sources though.
Trying to join the appended query with your last query.
1) Here´s the appended query:
let
Source = Table.Combine({MonthlyQuery,Daily})
in
Source
2) Here´s yours: TblAvgAll(2)
let
fnFirst14_ = (SYMBOL) =>
let
Source= Excel.Workbook(File.Contents("C:\Users\Imke\Documents\BI\Foren\Antworten\TN_RSI-On-
PowerpivotCleanDataSourcev3.xlsx")),
Data_Sheet = Source{[Item="Data",Kind="Sheet"]}[Data],
Header = Table.PromoteHeaders(Data_Sheet),
Filter = Table.SelectRows(Header, each ([SYMBOL] =SYMBOL)),
KeepFirst14 = Table.FirstN(Filter,14)
in
KeepFirst14,
//let
fnRSI_ = (AvgGain14, AvgLoss14, SYMBOL) =>
let
Source2= Excel.Workbook(File.Contents("C:\Users\Imke\Documents\BI\Foren\Antworten\TN_RSI-On-
PowerpivotCleanDataSourcev3.xlsx")),
Data_Sheet = Source2{[Item="Data",Kind="Sheet"]}[Data],
Header = Table.PromoteHeaders(Data_Sheet),
FilterSymbol = Table.SelectRows(Header, each ([SYMBOL] = SYMBOL)),
RemoveFirst13 = Table.Skip(FilterSymbol,13),
RemoveFirst14 = Table.Skip(FilterSymbol,14),
ListGain = List.Buffer(RemoveFirst14[Gain]),
ListLoss = List.Buffer(RemoveFirst14[Loss]),
ListDate = List.Buffer(RemoveFirst13[DATEA]),
Iterate = List.Generate(
()=>[Counter=0, Value_=AvgGain14],
each [Counter]<=List.Count(ListGain),
each [Counter=[Counter]+1,
Value_=([Value_]*13+ListGain{[Counter]})/14],
each [Value_]),
IterateLoss = List.Generate(
()=>[Counter=0, Value_L=AvgLoss14],
each [Counter]<=List.Count(ListLoss),
each [Counter=[Counter]+1,
Value_L=([Value_L]*13+ListGain{[Counter]})/14],
each [Value_L]),
Table = Table.FromColumns({Iterate, IterateLoss, ListDate})
in
Table,
Quelle = Excel.Workbook(File.Contents("C:\Users\Imke\Documents\BI\Foren\Antworten\TN_RSI-On-
PowerpivotCleanDataSourcev3.xlsx")),
Data_Sheet = Quelle{[Item="Data",Kind="Sheet"]}[Data],
#"Erste Zeile als Header" = Table.PromoteHeaders(Data_Sheet),
#"Entfernte Duplikate1" = Table.Distinct(#"Erste Zeile als Header", {"SYMBOL"}),
#"Andere entfernte Spalten" = Table.SelectColumns(#"Entfernte Duplikate1",{"SYMBOL"}),
#"Hinzugefügte benutzerdefinierte Spalte" = Table.AddColumn(#"Andere entfernte Spalten", "Function", each fnFirst14_
([SYMBOL])),
#"Function erweitern" = Table.ExpandTableColumn(#"Hinzugefügte benutzerdefinierte Spalte", "Function", {"Gain", "Loss"},
{"Gain", "Loss"}),
#"Gruppierte Zeilen" = Table.Group(#"Function erweitern", {"SYMBOL"}, {{"AvgGain14", each List.Average([Gain]), type
number}, {"AvgLoss14", each List.Average([Loss]), type number}}),
#"Hinzugefügte benutzerdefinierte Spalte1" = Table.AddColumn(#"Gruppierte Zeilen", "AvgGain", each fnRSI_([AvgGain14],
[AvgLoss14], [SYMBOL])),
#"AvgGain erweitern" = Table.ExpandTableColumn(#"Hinzugefügte benutzerdefinierte Spalte1", "AvgGain", {"Column1",
"Column2", "Column3"}, {"AvgGain", "AvgLoss", "DATEA"}),
#"Entfernte Spalten" = Table.RemoveColumns(#"AvgGain erweitern",{"AvgGain14", "AvgLoss14"})
in
#"Entfernte Spalten"
Getting all sorts of errors.