title: MDX - Calculated Member - Use Same Value Across All Time Periods
body: <p>I'm pretty new to MDX, but am stuck supporting a new tool and have a question about a request that recently came my way.  We have a cube of prescription data, where prescribers are assigned to different territories.  My client wanted a function to calculate the number of prescribers assigned to a territory, so I produced this:</p>
  
  <pre><code>COUNT(
       FILTER([M_Prescriber].[Prescriber].[Prescriber].Members*[Measures].[M-TRx],
       [M_Market_Product].[Product].[All]
       )                              
  )
  </code></pre>
  
  <p>Which gives a count of prescribers who have written a prescription in the time period.  The problem the client has is that this function produces a different result in each month because, naturally, some prescribers don't write prescriptions every month.  Is there a way to return the number of prescribers assigned to a territory without taking into account whether they have any prescription data in a particular month.  Or could I calculate this value in the latest time period and use that value in every time period?</p>
  
  <p>Let me know if I can provide more details.</p>