DAX Function to Calculate Average of Scores for Specific Variable IDs

This DAX function will filter specific variable IDs (286, 288, and 284), retrieve their associated score values, and then calculate the average across these three variables. Below is the implementation along with explanations.

Code Implementation

AverageScore := 
VAR SelectedVariableIDs = {286, 288, 284} -- Define the variable IDs to filter
VAR FilteredScores = 
    FILTER(
        ScoresTable, -- Table containing the scores
        ScoresTable[VariableID] IN SelectedVariableIDs 
    ) -- Filter the scores for selected variable IDs
VAR AverageScoreValue = 
    AVERAGEX(
        FilteredScores, -- The filtered table
        ScoresTable[Score] -- Column containing the score values
    ) -- Calculate the average of the score values

RETURN 
    AverageScoreValue -- Return the calculated average score

Explanation of Code

1. Variable Definition:

   • SelectedVariableIDs: A variable that holds an array of IDs to filter the scores from the ScoresTable.

2. Data Filtering:

   • FilteredScores: This uses the FILTER function to select rows in ScoresTable where the VariableID is in the list defined in SelectedVariableIDs.

3. Average Calculation:

   • AverageScoreValue: Utilizes the AVERAGEX function to iterate over the FilteredScores table, calculating the average of the Score column.

4. Return Statement:

   • The final output of the function is AverageScoreValue, which holds the average score of the filtered results.

Code Usage Example

To use the AverageScore in your Power BI report:

1. Create a measure with the provided DAX code.
2. Utilize this measure in your reports or dashboards to display the average score for variables 286, 288, and 284.

Example Measure Definition

Average_Score_Measure = 
VAR SelectedVariableIDs = {286, 288, 284}
VAR FilteredScores = 
    FILTER(
        ScoresTable,
        ScoresTable[VariableID] IN SelectedVariableIDs
    )
VAR AverageScoreValue = 
    AVERAGEX(
        FilteredScores,
        ScoresTable[Score]
    )
RETURN 
    AverageScoreValue

Summary

• The provided DAX function efficiently calculates the average score for a specific set of variable IDs.
• This solution adheres to best practices in DAX coding, including clear organization, inline comments, and logical flow.
• Implement this measure as part of your data model to gain insights into your variable scores easily.

For a deeper understanding of DAX and practical applications, consider exploring courses on the Enterprise DNA Platform that focus on advanced DAX techniques.