Whenever a table column is defined by a calculation expression containing a variable it is not possible to use the built-in summary statistics.
A variable can not store multiple values at a time and for summary statistics you need to store the multiple values in an array. The aggregator function of the expression editor could be used to setup the array and to calculate the summary statistics.
However, the output of this aggregator cannot be placed in the footer of a table. Template editing with BI studio or direct editing of the RDL file do not change the situation.
Aggregator results needs either be reported in a single value field, in another column of the result table or in a column of another table. A single value fields cannot be appended to a table, but you can position it fairly close.
The attached report and template contains 3 examples showing possible solutions.
Example 1: The Mean and RSD values are printed as individual name/value pairs. By choosing a generic table layout, the fields can be positioned right below the table. Do not activate the standard summary calculations, because the additional footer line will disturb the positioning of the Mean and RSD fields.
Example 2: If you intend to report multiple summary calculations based on multiple parameters you can use individual text fields to setup a matrix like shown in the example. Copy/paste allows you to build this 'matrix' fairly quick. Use the grid alignment to get the boxes sized and positioned.
Example 3: This example calculates the aggregator in a hidden table. The final results are displayed in a second table including further calculations (delta) based on the aggregator output.
(originally posted in OpenLAB Forum: https://zohodiscussions.com/openlabcdsforum#Topic/68030000000134001
2014 September 11 by betrich)