GRASS Vector Attributes

Q: How to edit GRASS Attributes?

A: Some commands allow specification of attributes, shown as: attr=string|cat|double|coords|dim

The meanings of these terms:

• string: text label attribute
• cat: vector ID number (cat: category, saved in both geometry file as well as attribute table)
• integer: integer precision attribute
• double: double precision attribute
• ...
• coords: vertex coordinates
• dim: number of dimensions (2D, 3D etc)

Modification of attributes

• Graphical editing can be done with the WxGUI Attribute Table Manager and the WxGUI Vector Digitizer
• Command line editing can be done with v.db.update and related modules.

Special cases

Two categories (with slash in the middle) can be assigned to a single vector feature in a single layer. This can happen e.g. when importing overlapping polygons:

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See also

• Vector Attribute Display
• Vector Database Management
• Vector map attribute transfer between connected tables
• Extracting coordinates of points and writing them to the attribute table