In AutoCAD Map 3D, you can set rules for the assignment of properties when you split and merge geospatial features. You can use expressions to define these rules.
For example, when splitting a parcel, you can base the land value of the resulting parcels on a calculation that you define. There are also choices for automatic calculations. You can assign the average value of all merged features to the resulting feature. You can divide the value of a feature evenly among its split features.
This table lists the options for split and merge rules and describes how to use them.
| Split Rules | Merge Rules |
|---|---|
| Calculation divides the value of the property for each resulting feature based on an expression you specify. For example, suppose the average parcel value for a neighborhood is 2000 times the value of the property Parcel_Acres. You can specify that Land_Value for each resulting parcel use that formula. This option is for numeric values only. | Average gives the new feature a value that is an average of the original features. This option is for numeric values only. |
| Copy gives each new feature an exact copy of the original property value. The original is unchanged. | Calculation determines the value of the property for the resulting feature based on an expression you specify. For example, you can specify that Net_Value for each resulting parcel equal Imp_Value minus Land_Value. (This option is available for numeric properties only.) |
| Divide gives each resulting feature an equal fraction of the original value. This option is for numeric values only. | Concatenation appends the values for each merged feature to create the value for the new feature. |
| Empty leaves the new property value empty for each new feature. The original is unchanged. | Count gives the new feature the value of the total number of features merged to produce it. This option is for numeric values only. |
| Expression Specifies an expression for string properties. | Empty leaves the new property value empty for the new feature. The original features are unchanged. |
| Proportional divides the value of the property for each resulting feature proportionally, based on a value you specify. For example, you can assign a proportional value for Parcel_Acres based on the value of the area of the resulting parcels. This option is for numeric values only. | Expression Specifies an expression for string properties. |
| First Selected gives the new feature the value of the first feature you select for the merge. This option is meaningful only if you select the objects for the merge sequentially. (First Selected is the default for all properties except numeric ones.) | |
| Last Selected gives the new feature the value of the last feature you select for the merge. This option is meaningful only if you select the objects for the merge sequentially. | |
| Maximum gives the new feature the maximum value available in all features in the merge. (This option is available for numeric properties only.) | |
| Median gives the new feature the median value calculated from all features in the merge. (This option is available for numeric properties only.) | |
| Minimum gives the new feature the minimum value available in all features in the merge. (This option is available for numeric properties only.) | |
| Standard Deviation gives the new feature the standard deviation value calculated from all features in the merge. (This option is available for numeric properties only.) | |
| Sum gives the new feature the total value of all features in the merge. (This option is available for numeric properties only.) |