If you have data attached to map objects that will be edited, you can proportion the data for each field to match the new object(s). This is called data aggregation or disaggregation, depending on whether you are combining or splitting objects. MapInfo Pro calculates new data values for the object depending on how you specify the aggregation or disaggregation.
When combining objects, you can choose from several methods of data aggregation, including:
- Sum - adds the field values from the original objects to create a total for the field in the new object.
- Average - averages the field values from the original objects.
- Weighted average - gives more weight to one value over another when averaging. You can choose a numeric field in your table as the weighting factor or choose area (where the weighted average is based on the relative geographic area of the regions to be combined).
- Value - stores a specific value in the field of the new object.
- No Change - maintains the value of the target object in the new object.
When splitting or erasing portions of a map object, you can choose from:
- Blank - removes the original value of the target object.
- Value - maintains the original value of the target object.
- Area proportion - removes a portion of the original value based on the size of the new object.
For any of the editing operations in the Edit group on the SPATIAL tab, you can elect not to bring over any data at all by choosing the No Data check box. You might do this, for instance, if you are only editing map objects for presentation purposes and do not need any data associated with the objects.
The Data Aggregation (or Data Disaggregation) dialog box displays after you have set the target, chosen the modifying object, and chosen an editing operation. In these dialog boxes, you must specify how you want the data calculated for each field. Once you are satisfied with the aggregation method, you can carry out the editing operation.