MDX - How to group results to calculate the average

Question

Hi,
I have the following MDX query which selects total unique visits per day between a range of my choosing:
WITH MEMBER [Measures].[MyAvg] AS
Round( AVG(
EXCEPT([Dim Date].[Day Of Week].Members,
{[Dim Date].[Day Of Week].[All].&[1],[Dim Date].[Day Of Week].[All].&[7],[Dim Date].[Day Of Week].[All].UNKNOWNMEMBER}
), [Measures].[UniqueVisitsDay]
), 2)
SELECT { [Measures].[MyAvg] } ON COLUMNS,
NON EMPTY { [Dim Date].[Year Month Date].[PK Date].&[2013-03-01T00:00:00]:[Dim Date].[Year Month Date].[PK Date].&[2013-03-31T00:00:00] } ON ROWS
FROM
[MyCube];
Which gives me the following results:
01/03/2013 634
02/03/2013 16
03/03/2013 19
04/03/2013 698
05/03/2013 704
06/03/2013 692
07/03/2013 774
08/03/2013 755
09/03/2013 9399
10/03/2013 19990
11/03/2013 775
12/03/2013 835
13/03/2013 868
14/03/2013 900
15/03/2013 844
17/03/2013 19
18/03/2013 248
19/03/2013 920
20/03/2013 958
21/03/2013 1092
22/03/2013 798
23/03/2013 21
24/03/2013 10
25/03/2013 731
26/03/2013 770
27/03/2013 537
28/03/2013 300
29/03/2013 28
30/03/2013 8
31/03/2013 4
What I need to do is get the average of this set of results over the month.  I am expecting this answer:
1478.233333 (which is total unique hits - 44347 / total rows - 30)
But when I change my MDX code to this:
WITH MEMBER [Measures].[MyAvg] AS
Round( AVG(
EXCEPT([Dim Date].[Day Of Week].Members,
{[Dim Date].[Day Of Week].[All].&[1],[Dim Date].[Day Of Week].[All].&[7],[Dim Date].[Day Of Week].[All].UNKNOWNMEMBER}
), [Measures].[UniqueVisitsDay]
), 2)
SELECT { [Measures].[MyAvg] } ON COLUMNS,
NON EMPTY { [Dim Date].[Year Month].[Mar 2013]:[Dim Date].[Year Month].[Mar 2013] } ON ROWS
FROM
[MyCube];
I get the following result:
MyAvg
Mar 2013 9868
Actual: 9868  
Expected: 1478.233333
What am I doing wrong?
Thanks,
Rob

Answer 1

Hi Rob,
In SQL Server Analysis Serviceswe do not have a measure Average aggregation type. Fortunately, we have Sum and Count, and since Average = Sum / Count, we can build our own Average aggregation when we need one. Here is a blog about how to create a average
measure, please refer to the link below.
Average Aggregation in Analysis Services
Regards,
Charlie Liao
TechNet Community Support