DAX Function for Year-To-Date (YTD) Calculation

The following DAX function computes the Year-To-Date (YTD) value for a specified measure, considering the context of the selected year. This function can be used in Power BI or any tool that supports DAX queries.

Code Overview

YTD_Sales = 
VAR SelectedYear = YEAR(TODAY())
RETURN
    CALCULATE(
        SUM(Sales[SalesAmount]),        // Replace with your measure
        FILTER(
            ALL('Date'),                // Adjust the Date table as required
            'Date'[Year] = SelectedYear &&
            'Date'[Date] <= TODAY()
        )
    )

Function Breakdown

1. Variable Declaration:

   • SelectedYear: Captures the current year using TODAY() for a dynamic year value.

2. CALCULATE Function:

   • It modifies the filter context to evaluate the SUM of Sales[SalesAmount] based on the specified conditions.

3. FILTER Context:

   • ALL('Date'): Removes existing filters from the ‘Date’ table to apply our new filters.
   • The filter checks that only dates within the SelectedYear up to today’s date are included.

Documentation

Function: YTD_Sales

• Purpose: Calculates the Year-To-Date total for sales based on the current year.
• Parameters:
  • None (implicitly uses the current date and the Sales table).
• Return type: Numeric (Sales Amount).
• Exceptions: Assumes a proper Date table with a continuous date range and a Sales table.

Input Validation

• Ensure the Sales and Date tables exist with the correct columns.
• SalesAmount should be a numeric field.
• Date table must include a date column covering all necessary dates.

Commentary

• The use of YEAR(TODAY()) allows for dynamic calculation for any year based on the current date.
• The ALL() function is critical in resetting filters to ensure YTD calculations from the start of the year.

Code Usage Example

Once the function is defined, you can use it in any visualizations or measures in your Power BI report:

1. Create a Card or Table visualization.
2. Insert the YTD_Sales measure to see the Year-To-Date sales total.

CARD Visual: = [YTD_Sales]

Conclusion

This DAX function provides an efficient approach for calculating YTD metrics, which is essential for reporting and analysis in business intelligence tools like Power BI. For a deeper understanding and advanced use cases, consider exploring courses available on the Enterprise DNA Platform.