Geographic Information Systems Using ESRI ArcGIS 9.3 Advanced Editing: Attribute Table

ATTRIBUTE TABLE Multiple field editing Field calculator Editing one field inserting a single value or basing upon a formula right click on the field name

ATTRIBUTE TABLE Multiple field editing Field calculator Editing all the record or only the selected ones

ATTRIBUTE TABLE Multiple field editing Field calculator Simply type in the new value/label Text must be placed between quotation marks

ATTRIBUTE TABLE Multiple field editing Field calculator Run the calculator

ATTRIBUTE TABLE Multiple field editing Field calculator Entering a single value in one field for all the selected records Result

ATTRIBUTE TABLE Multiple field editing Field calculator Editing using formulas Type in the formula (generally referring to another field)

ATTRIBUTE TABLE Multiple field editing Field calculator Editing using formulas On the right, the available funcions for the selected type of data is listed

ATTRIBUTE TABLE Multiple field editing Field calculator Editing using formulas Result

ATTRIBUTE TABLE Multiple field editing Field calculator Activating the “Advanced” function it is possible to make complex calculation The VBA (Visual Basic for Application) programming language is to be used

ATTRIBUTE TABLE Multiple field editing Field calculator Examples of VBA scripts can be found in the help file. Internet gives the possibility to download a huge number of useful scripts for many purposes.

ATTRIBUTE TABLE Multiple field editing Field calculator It is possible to run the Field Calculator also outside of an Editing session; in this case, changes cannot be undone. A warning message is shown

ATTRIBUTE TABLE Calculate Geometry It is possible to calculate gometrical features of the objects, storing them in a field of the attribute table

ATTRIBUTE TABLE Calculate Geometry Points The only geometrical features for points are the X and Y position (i.e. the coordinates)

ATTRIBUTE TABLE Calculate Geometry Points Add two new fieds to store the coordinates (double precision, at least 7 digist to the left of the digital point)

ATTRIBUTE TABLE Calculate Geometry Points Right click on the field name and select “Calculate Geometry”

ATTRIBUTE TABLE Calculate Geometry Points Select the desired geometric property, the coordinate system and the unit

ATTRIBUTE TABLE Calculate Geometry Points Result

ATTRIBUTE TABLE Calculate Geometry Polylines For polylines, more properties are available: Length, Coords of startpoint Coords of endpoint Coords of centroid

ATTRIBUTE TABLE Calculate Geometry Polygons For polygons, it is possible to calculate: Area Perimeter Coords of centroid

ATTRIBUTE TABLE Calculate Geometry Polygons For polygons, it is possible to calculate: Area Perimeter Coords of centroid

ATTRIBUTE TABLE The attribute table of every shapefile is stored as a.dbf file (i.e. as a file that can be handled by a spreadsheet, such as Excel)

ATTRIBUTE TABLE The attribute table of every shapefile is stored as a.dbf file

ATTRIBUTE TABLE The dbf file associated with shapefiles can be handled by a spreadsheet, such as Excel. This allows to modify, create and erase fields, make calculations and draw graphs.