1. Mastering ArcGIS Attribute Data (Continued)
Chapter 5
Chapter 6
Attribute Data (Continued)
Copyright © McGraw-Hill Education. Permission required for reproduction or display.

2. Editing and calculating fields
Mastering ArcGIS
Chapter 5
Editing and calculating fields
Copyright © 2015 by Maribeth H. Price

3. Editing fields Open Editor toolbar Start editing* Type edits in fields
Mastering ArcGIS
Chapter 5
Editing fields
Open Editor toolbar
Start editing*
Type edits in fields
Save edits, stop editing
* select the layer to edit if asked
Copyright © 2015 by Maribeth H. Price

4. Calculating fields Add a new field if necessary
Mastering ArcGIS
Chapter 5
Calculating fields
Add a new field if necessary
Consider whether you need decimal places!
Copyright © 2015 by Maribeth H. Price

5. Field calculator Right-click field to calculate
Mastering ArcGIS
Chapter 5
Field calculator
Right-click field to calculate
Usually field should be EMPTY
Be careful! Calculations can’t be undone unless you are in an edit session
Enter expression
Copyright © 2015 by Maribeth H. Price

6. Calculating geometry measures
Mastering ArcGIS
Chapter 5
Calculating geometry measures
Feature geometry measures can be calculated
Geodatabases are automatically calculated
Shapefiles must be manually calculated
Geometry can be calculated for:
Line data (length)
Polygon data (area)
Use Calculate Geometry menu option on field right-click menu
Copyright © 2015 by Maribeth H. Price

7. Geodatabase geometry measures
Mastering ArcGIS
Chapter 5
Geodatabase geometry measures
Automatically created and maintained
Usually appear at end of table
Shape_Area field
Shape_Length field
Units will match units of the coordinate system
Copyright © 2015 by Maribeth H. Price

8. Shapefile geometry measures
Mastering ArcGIS
Chapter 5
Shapefile geometry measures
Shapefiles DO NOT create or maintain area/length fields automatically!
Must be created and updated manually
Some functions and operations can change the lengths and areas of features
If you find an AREA field there is no guarantee that it is correct
Copyright © 2015 by Maribeth H. Price

9. Mastering ArcGIS
Chapter 5
Be careful!
AREA/LENGTH/PERIMETER fields in shapefiles are NOT updated when features change.
Before
After
Copyright © 2015 by Maribeth H. Price

10. Calculating feature geometry
Mastering ArcGIS
Chapter 5
Calculating feature geometry
Right-click empty or incorrect field to update
Choose type, coordinate system, and units
Copyright © 2015 by Maribeth H. Price

11. Test yourself: True or False?
Mastering ArcGIS
Chapter 5
Test yourself: True or False?
A field named AREA in a shapefile will always have the correct area?
False. Shapefile area fields are not automatically maintained.
A field named AREA in a geodatabase will always have the correct area?
False. Automatically updated fields in a geodatabase are called Shape_Area.
Copyright © 2015 by Maribeth H. Price

12. Importing tables Mastering ArcGIS Chapter 5
Copyright © 2015 by Maribeth H. Price

13. Importing text (ascii) tables
Allowed in ArcGIS
Tab-delimited
Comma-delimited
Not allowed
Fixed-column
Copyright © 2015 by Maribeth H. Price

14. Importing text (ascii) tables
Also Allowed in ArcGIS
Excel
Allowed in ArcGIS Using ODBC
MS Access Tables
SQL Database Tables
Copyright © 2015 by Maribeth H. Price

15. Mastering ArcGIS
Chapter 5
Importing Excel files
Excel worksheets with suitable layout can be opened as tables in ArcGIS
Most functions that do not involve changing the file will work (sort, query)
Tables cannot be changed or edited
Copyright © 2015 by Maribeth H. Price

16. Excel file requirements
Mastering ArcGIS
Chapter 5
Excel file requirements
First row must contain field headings with legal field names as defined earlier
No blank rows or formulas should be used
Each column should contain only text or only numbers.
It is helpful for each column to be formatted as text, numeric, etc.
ArcMap cannot open files that are already open in Excel—they must be closed first
Copyright © 2015 by Maribeth H. Price

17. Mastering ArcGIS
Chapter 5
Acceptable Worksheet
Columns formatted as text or numeric
Legal field names
No formulas or blank lines
Decimal degrees = degrees + minutes/60 + seconds/3600
Copyright © 2015 by Maribeth H. Price

18. Excel Workbooks and worksheets
Mastering ArcGIS
Chapter 5
Excel Workbooks and worksheets
An Excel workbook file (.xls) may contain more than one worksheet.
By default there are three named Sheet1, Sheet2, Sheet3.
There may be one or more named worksheets.
ArcMap can only open one worksheet at a time.
You will open the workbook like a folder and select a single worksheet
Copyright © 2015 by Maribeth H. Price

19. Adding an Excel worksheet
Mastering ArcGIS
Chapter 5
Adding an Excel worksheet
2. Open workbook file like a folder
1. Add data button
3. Add named worksheet, or the first unnamed worksheet.
Copyright © 2015 by Maribeth H. Price

20. Excel Worksheet in ArcMap
Mastering ArcGIS
Chapter 5
Excel Worksheet in ArcMap
You can use x-y locations in a table to produce points on a map.
But first you must know the coordinate system of these locations. What is this one?
Copyright © 2015 by Maribeth H. Price

21. Displaying x-y values from a table
Geographic coordinate system (GCS)
A table with x-y values can be displayed as points.
Use any coordinate system, but you must know what it is.
Copyright © 2015 by Maribeth H. Price

22. Use the Edit button to define the coordinate system.
Mastering ArcGIS
Chapter 5
Display XY Data
Degrees indicate a geographic coordinate system (GCS). NAD83 is the most common.
Other tables might have units in UTM meters, State Plane feet, etc. You must know the coordinate system to create correctly located points.
Use the Edit button to define the coordinate system.
Copyright © 2015 by Maribeth H. Price

23. Oregon climate stations
Mastering ArcGIS
Chapter 5
Oregon climate stations
Stations appear as points on the map, an “event layer”
Export to shapefile or feature class to keep permanently
Copyright © 2015 by Maribeth H. Price

24. Demo
Copyright © 2015 by Maribeth H. Price