@MOVSUM

The @MOVSUM calculation function for Essbase applies a moving sum to the specified number of values in an input data set. @MOVSUM modifies a data set for smoothing purposes.

Syntax

@MOVSUM (mbrName [, n [, XrangeList]])

Parameters

mbrName: Any valid single member name, or a function that returns a single member.
n: Optional. A positive integer value that represents the number of values to sum. The default is 3.
XrangeList: Optional. A valid member name, a comma-delimited list of member names, cross dimension members, or a member set function or range function (including @XRANGE) that returns a list of members from the same dimension. If XrangeList is not specified, Essbase uses the level 0 members from the dimension tagged as Time.

Notes

For example, if you specify 3 members of the Time dimension in the Sample Basic database, @MOVSUM at Mar is the sum of the values for Jan, Feb, and Mar; @MOVSUM at Apr is the sum of the values for Feb, Mar, and Apr. However, Jan and Feb have no @MOVSUM value, and are called trailing members. Trailing members are copies of the input values. If you wish to assign different values to trailing members, use @MOVSUMX instead.
The @MOVSUM function calculates a trailing, rather than a centered, sum. This example illustrates the difference:
```
   Trailing Sum           Centered Sum
    1   2   3              1   2   3
            6                  6
```
While calculating the moving sum, @MOVSUM skips #MISSING values. For example, if one value out of three is #MISSING, Essbase adds the remaining two values.
If you use an Essbase member set function to generate a member list for the XrangeList parameter (for example, @SIBLINGS), to ensure correct results, consider the order in which Essbase sorts the generated member list. For more information, see the help topic for the member set function that you are using.
When you use @MOVSUM in a calculation script, use it within a FIX statement. Although FIX is not required, using it may improve calculation performance.
When you use @MOVSUM across a large range in a sparse dimension, you may need to increase the size of the calculator cache.

Example

The following example is based on the Sample Basic database. Assume that the Measures dimension contains an additional member, Mov Sum.

"Mov Sum" = @MOVSUM(Sales,3,Jan:Jun);

In this example, @MOVSUM smoothes sales data for the first six months of the year (Jan through Jun). The results of @MOVSUM can be used with @TRENDto forecast average sales data for a holiday season (for example, October through December).

This example produces the following report:

          Colas   New York   Actual              
              Sales     Mov Sum 
              =====     =======   
Jan            678        678   
Feb            645        645   
Mar            675       1998   
Apr            712       2032   
May            756       2143   
Jun            890       2358