Power BI: Calculate difference column - powerbi

Question

I am facing an issue while calculating differences in the matrix. For example,
In the below image as you can see where there is a blank, the difference is coming 0 whereas it should come 3. I have used the following formula for calculating difference:
Diff =
CALCULATE (
DISTINCTCOUNT ( 'Question and Answer'[Respondent ID] ),
FILTER (
'Question and Answer',
'Question and Answer'[Start Date] = MAX ( 'Question and Answer'[Start Date] )
)
)
- CALCULATE (
DISTINCTCOUNT ( 'Question and Answer'[Respondent ID] ),
FILTER (
'Question and Answer',
'Question and Answer'[Start Date] = MIN ( 'Question and Answer'[Start Date] )
)
)
Any help would be appreciated. Thanks!

Answer 1

I might be mistaken, but it looks like you're calculating the difference between the start and end date of your data, filtered on gender. 'Rather not say' only has data points on one day, therefore it would follow the difference is zero.
What happens is: 3-3 = 0.
What you could do to solve this is to build in logic that evaluates if the min and max start dates are equal, and pass in 0 instead of the value.
Diff =
CALCULATE (
DISTINCTCOUNT ( 'Question and Answer'[Respondent ID] ),
FILTER (
'Question and Answer',
'Question and Answer'[Start Date] = MAX ( 'Question and Answer'[Start Date] )
)
)
- **IF(DATEDIFF(MAX('Question and Answer'[Start Date]),MIN('Question and Answer'[Start Date]),DAY) = 0, 0** ,
CALCULATE (
DISTINCTCOUNT ( 'Question and Answer'[Respondent ID] ),
FILTER (
'Question and Answer',
'Question and Answer'[Start Date] = MIN ( 'Question and Answer'[Start Date] )
)
)
)
The line of code between the two asterix causes the code to work as intended.