Editing Tabular Data Francisco Olivera, Ph.D., P.E. Department of Civil Engineering Texas A&M University

Overview Editing tabular data manually. Editing tabular data automatically. Creating new tabular data.

Edit Mode To make a table editable, in the Table GUI, click on the Table/Start Editing menu. The headers of all editable fields will display in standard (vertical) font instead of italics.

Editing Cells To edit individual table cells, click on the field header (it will change its color), then on the Edit tool, and then on the cell you want to edit.

Editing Fields To edit the values of all selected records of a table field, click on the field header (it will change its color), then on the Calculate button, and then fill the Field Calculator panel. The field calculator window can be filled with a string, a number, a mathematical expression or an Avenue expression, depending on the field type.

Adding Fields To add a new field to a table, click on Edit/Add Field menu, and then define the field you want to add. Fields can be numbers, strings, booleans or dates, and can have different widths and number of decimal digits (if numbers). The field values can be filled one- by-one with the Edit tool, or all- at-once with the Calculate button.

Adding Records To add a new record to a table, click on Edit/Add Record menu. Do not add records to Theme Attribute Tables, because they would not be associated to any feature shape. If a feature is to be added to a Theme, it should be added by editing the Theme from the View GUI.

Overview Editing tabular data manually. Editing tabular data automatically. Creating new tabular data.

Updating Attributes Some attributes need to be updated when the feature geometry is modified (i.e., splitting lines, merging lines, splitting polygons, merging polygons, etc.). Depending on the type of feature property an attribute describes, it can be updated in different ways: Extensive properties (e.g., weight) refer to the entire feature, and have to be updated proportional to the area of the new polygons or length of the new lines. Intensive properties (e.g., density) refer to a unit area or length, and do not need to be updated.

… After Splitting Features Attributes of the resulting features can be: Blank Copy (default) Proportion Shape length (for lines) Shape area (for polygons) Shape perimeter (for polygons)

… After Merging Features Attributes of the resulting lines can be: Blank Copy (default) Proportion Add Average Shape length (for lines) Shape area (for polygons) Shape perimeter (for polygons)

Attribute Updating Rules To set the automatic attribute updating rules, before splitting or merging features, in the Theme Properties window, click on Editing, and then fill the Attribute Updating panel. Select the field to be updated, check the Single box, and set the Union and Split rules.

Updating Feature Geometry If a feature dataset does not have the Length or Area and Perimeter fields, or if they store incorrect values, they can be created or corrected automatically. Load the CRWR-Vector extension, make the Theme active, and click on the CRWR-Vector/Update Feature Geometry menu.

Adding Record Number Even if not displayed in the attribute table, all records of feature datasets have a unique identification number called Record Number. The record number can be automatically added to the attribute table. Load the CRWR-Vector extension, make the Theme active, and click on the CRWR- Vector/Add Record Number to Table menu. The Record number will be stored in a field called Recno.

Adding Coordinates The coordinates of point features and polygon feature centroids can be automatically added to the attribute table. Load the CRWR-Vector extension, make the Theme active, and click on the CRWR- Vector/Add XY to Table menu. The coordinates will be stored in two fields called X-coord and Y- coord.

Overview Editing tabular data manually. Editing tabular data automatically. Creating new tabular data.

Creating New Tables New stand-alone tables (i.e., not related to geographic data) can be created by clicking on the Tables icon in the Project window and then on the New button. The new table would be of dbf format and will have no fields or records. Fields, records and values have to be added one-by-one manually.