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AlanRGroskreutz's avatar
AlanRGroskreutz
Helper II
6 years ago
Solved

DAX Moving hourly average/count

Hi all, I'm having a terrible time trying to get my time span filter working for a moving count.  I am working on an Air Traffic Predictor model that we'll show the occupancy of air traffic sectors....
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  • TaylorClark's avatar
    TaylorClark
    6 years ago

    AlanRGroskreutz, let me know if this is what you're looking for:

     

     

    rolling entry count =
  var windowStart = SELECTEDVALUE(results[Entry 20 min Date time bin])
  var windowEnd = windowStart + TIME(0, 20, 0)
  return CALCULATE(
    COUNT(results[Entry Time]), // After we change filters, do our calculation
    FILTER( // Replace any existing filter on the [Entry 20 min Date tiem bin] column with one that looks at the period we want
      ALL(results[Entry 20 min Date time bin]), // Look through *all* values in the column, ignoring any existing filters
      [Entry 20 min Date time bin] >= windowStart && [Entry 20 min Date time bin] <= windowEnd // Keep those rows which are in our time range
  )
)

     

     

     
    Matrix with results
     
    The key here is to use ALL to clear any groupings/filters that are applied to look at rows of your table which might be filtered out in the scope that the measure is being executed in. 
AlanRGroskreutz's avatar
AlanRGroskreutz
Helper II
6 years ago

Sorry TaylorClark , I found a problem, but not with your code, with an assumption I had made.  I was assuming that each sector would have at least one flight entering it in each 20 min period, so when I was creating the 20 min Date-time bins, I was basing it off of the entry times.

The problem that happens is that for the rolling count if you have a period that has 0 entries, it doesn't just use zero for that 20 min bin and count the next two, it just skips that bin as if it didn't exist.  Am I going to have to create a 20 min Date-Time bin table to solve this?

AlanRGroskreutz's avatar
AlanRGroskreutz
Helper II
6 years ago

Yup, making a separate table with all the Date-Tim bins was the solution. I then had to replace the 'result' Date time bin references with references to the new table.

 

Thanks again.