CreateMovingAverages.cs

// Moving Average

#r "Microsoft.VisualBasic"
using Microsoft.VisualBasic;
using System.Text.RegularExpressions;

// Select a measure
var offsetMeasure = Model.SelectMeasure();

// Select an offset column
string offsetColumn = SelectColumn(Model.Tables["Dates"].Columns.Where(
                                       col => col.Name.Contains("Offset") & (col.Name.Contains("Week") | col.Name.Contains("Month") | col.Name.Contains("Quarter"))))
                          .Name;


// Get the interval
string strInterval = Interaction.InputBox(
    Prompt: "Enter the interval for the offset calculation:", Title: "Interval",
    DefaultResponse: "3");
if (strInterval == "") {
  Error("No interval provided");
  return;
}

string dax = @"

VAR __CurrentOffset = SELECTEDVALUE( Dates[" + offsetColumn + @"] )

VAR __MovAvg = 
    CALCULATE(
    [" + offsetMeasure.Name + @"],
        FILTER(
            ALL(Dates),
            Dates[" + offsetColumn + @"] <= __CurrentOffset &&
            Dates[" + offsetColumn + @"] <= __CurrentOffset -" + strInterval + @" + 1
        )
    )

RETURN
    __MovAvg

";

// Split by CamelCase
var words = Regex.Matches(offsetColumn, @"[A-Z][a-z]*")
                .Cast<Match>()
                .Select(m => m.Value)
                .ToList();

// Initialize variable
string period = "";

// Get the middle part (e.g., "Year", "Day", "Month")
if (words.Count == 3) {
  period = words[1];
}

// Build measure name
string measureName =
    strInterval + " " + period + " MA - " + offsetMeasure.Name;

// Add the measure
Model.Tables["1M"].AddMeasure(measureName, dax, "TI\\Moving Averages").FormatDax();