AGGREGATION subcommand (SPATIAL ASSOCIATION RULES command)
The AGGREGATION subcommand specifies the aggregation methods for data and
maps.
- Aggregation is necessary when there are more records in the data than there are features in the map. For example, you have data records for individual counties but you have a map of states.
- You can specify the aggregation method for continuous and ordinal fields. Nominal fields are aggregated based on the modal value.
- AGGMAP=NO | YES
- The
AGGMAPkeyword specifies if aggregation is applied to both data and maps. The default value isNO, and aggregation is applied only to data. - CONTINUOUS=MEAN | MEDIAN | SUM
- The aggregation method for continuous fields. The default value is
MEAN. - ORDINAL=MODE | MEDIAN | HIGHEST | LOWEST
- The aggregation method for ordinal fields. The default value is
MODE.
Measurement level
For data sources that are not IBM® SPSS® Statistics format data files, measurement level is automatically assigned based on the rules in the following table.
| Condition | Measurement Level |
|---|---|
| Format is dollar or custom-currency | Continuous |
| Format is date or time (excluding Month and Wkday) | Continuous |
| All values of a variable are missing | Nominal |
| Variable contains at least one non-integer value | Continuous |
| Variable contains at least one negative value | Continuous |
| Variable contains no valid values less than 10,000 | Continuous |
| Variable has N or more valid, unique values* | Continuous |
| Variable has no valid values less than 10 | Continuous |
| Variable has less than N valid, unique values* | Nominal |
* N is the user-specified cut-off value. The default is 24.