feature manipulation - portland state university
TRANSCRIPT
10/30/2009
1
Vector Map Manipulation Tools
Christopher Rowlette
Geog 575
10/26/2009
Feature Manipulation
• 1.) Dissolve ‐‐‐‐ Data Management Tools/Generalization Toolset
• 2.) Clip ‐‐‐‐ Analysis Tools/Extract Toolset
• 3.) Append ‐‐‐‐ Data Management Tools/General Toolset
• 4.) Select ‐‐‐‐ Analysis Tools/Extract Toolset
• 5.) Eliminate ‐‐‐‐ Data Management Tools/Generalization Toolset
• 6.) Update ‐‐‐‐ Analysis Tools/Overlay Toolset
• 7.) Erase ‐‐‐‐ Analysis Tools/Overlay Toolset
• 8.) Split ‐‐‐‐ Analysis Tools/Extract Toolset
10/30/2009
2
Dissolve – aggregates features in a feature layer that have the same attribute value or values.
**Dissolve is used to create a simplified coverage from one that is more complex. Example: A state’s counties can be dissolved into geographic regions.
Clip – creates a new layer that includes only those features of the input layer that fall within the area
extent of the clip layer.
10/30/2009
3
Append – creates a new layer by piecing together two or more layers.
*Append checks for the existence of the coverage, verifies that the list of feature attribute table items matches the items in previously entered coverages and calculates Tic‐ID and feature User‐ID offsets according to the specified offset option.
Select – creates a new layer that contains features selected from a user‐defined query expression.
*Block groups of UGB before select.*
*Block groups of UGB after select: POP>=2870
10/30/2009
4
Eliminate – creates a new layer by removing features that meet a user defined query expression.
*Selected county lines for removal from state layer.*
*New layer with selected features (county lines) removed.*
Update – uses a “cut and paste” operation to replace the input layer with the update layer and its features.
10/30/2009
5
Erase – removes from the input layer those features that fall within the area extent of the erase layer.
*UGB and surrounding counties before erase procedure.*
*UGB has been removed from the input layer.*
Split – divides the input layer into two or more layers.