Server User Guides > Survey Tabulation > Working with hierarchical data > The base in grid tables > Setting up bases for grid iterations
 
Setting up bases for grid iterations
The following example demonstrates how to setup bases for grid iterations to include all respondents. The base expressions includes a higher-level question that forces the base to include null values:
double[0..100] precision(5) scale(1) axis("{base1 'Base' base() [IsHidden=True], b 'Base' base('^.Respondent_Number is not null')
[IsHidden=True], s 'Sum [Hidden]' sum(Grid_AE[{..}].AE) [IsHidden=True], m 'Mean' derived('@1 / @2') [Decimals=1]}");
By default, null iterations are omitted because they can hinder performance. The EvaluateEmptyIterations custom property must be applied to the grid in the metadata in order to override the default behavior. For example:
Grid_AE "Attitudinal equity score"
  [
    EvaluateEmptyIterations = true
  ]
loop
When EvaluateEmptyIterations custom property is set to true, all iterations, including empty iterations that do not exist in the CDSC, are returned.
Refer to “Custom properties in use in UNICOM Intelligence products” in the UNICOM Intelligence Developer Documentation Library for more information regarding custom properties.
See also
The base in grid tables