Unit Two: Attribute Tables In this unit… ► Features & properties Basic features Rearranging columns Freezing & Sorting columns Field Labels & Hiding fields ► Editing Tables Entering Edit Mode (!?) Changing Attribute values ► Review ► Opening Tables ► Arranging and Moving Windows
Unit Two – Attribute Tables 2 Review – GIS Data Types ► “ Feature Data” Data Structures: ► “Shapefiles” ► “Coverages” ► “Geodatabases” Examples: ► Lakes ► Houses ► Roads ► “Image Data” Data Structures: ► image e.g. “Digital Raster Graphic” (DRG) ► “GRID” ► “Digital Elevation Model” (DEM) Examples: ► Aerial photo ► Image of USGS topo
Unit Two – Attribute Tables 3 Review Each “Record” in the table… …Connected to a “Feature” in the “Feature Data” THIS is the heart of GIS! THIS is the heart of GIS!
Unit Two – Attribute Tables 4 Review Attribute Tables – Just Columns & Rows. When tables contain the attributes of geospatial features, the power of the data in the table is expanded… every value can be represented graphically on a map!
Unit Two – Attribute Tables 5 Review We want “Attributes” of a “Layer”, so… Opening an Attribute Table Context is Layer …right click and select “Open Attribute Table”
Unit Two – Attribute Tables 6 Arranging and Moving Windows Here’s the issue: windows that you open land on top and stay on top. The Window menu is unlike those you would find in most other Windows programs: ► ► no tiling, ► ► no cascading, ► ► no switching between windows. Big change for AV 3.x users! Learn to cope.
Unit Two – Attribute Tables 7 Arranging and Moving Windows You can always minimize windows… They go to the bottom of the screen. ► ► Better: re-arrange the windows altogether But look… both windows are “Active” ► ► You can take action in both windows…and ► re-size them by dragging the corners or borders. ► Just drag them using the title bar…
Unit Two – Attribute Tables 8 Table Features and Properties ► ► Some window features: Current record Record advance Show All / Show Selected toggle Selected record counter Options button Active Make Column Active Select a Row ► ► Click HERE to… ► ► and HERE to… Table Option Menu Basics
Unit Two – Attribute Tables 9 Table Features and Properties Rearranging Columns Move Column left or right Change Column Width ► ► Click AND DRAG to… ► ► Click and drag EDGES to…
Unit Two – Attribute Tables 10 Table Features and Properties FreezingandSorting ► ► Context for Field or data actions is “Column” – right- click in header ► ► “freezing” - “unfreezing” toggle: frozen columns stay on the left of the table and do not scroll. ► “Active” ► You can sort the “Active” column from here as well.
Unit Two – Attribute Tables 11 Table Features and Properties Field Labels and Hiding Fields Table context menus don’t set ANY table properties… Instead: “Layer Context Menu”… in the T.O.C. pane of the ArcMap window … right-click on the Layer… and pick “Properties” … to change the field’s label, enter a new alias here. 4 This checkbox makes the field “ 4 isible”. Population
Unit Two – Attribute Tables 12 Your turn… Chapter 2: Step 1 through 9
Unit Two – Attribute Tables 13 Editing Tables Warning: You are now leaving the safe, virtual ArcMap Environment.
Unit Two – Attribute Tables 14 Editing vs Data Definition Know what you want! Editing: ► ► means changing attribute values. ► ► requires “Edit Mode” Adding & Deleting Fields: ► ► is not considered “Editing” ► ► can’t be done in edit mode Delete a field: the context is an existing field, so right click the field’s header Add a Field: Options menu, (no context) and complete the field definition dialog. Table Option Menu
Unit Two – Attribute Tables 15 Adding Fields Field Type Guidelines: ► Use ‘text’ for fields that contain alpha, or numbers that won’t be used for math Like zip codes: you don’t want the text ‘03824’ to display as a number 3,824 ► Use ‘short’ or ‘long’ for integers (numbers that will require no decimal places i.e. ‘scale’ = 0) ‘Short’ for numbers between -32,000 and +32,000 ‘Long’ for numbers between about -2 billion and +2 billion ► Use floating point for fractional numbers (require decimal places) Single floating point – aka ‘float’ – for precision < 7 Double floating point – aka ‘double’ – for precision >6 Don’t worry too much: If you ask for the wrong kind of field, for the number of decimal places requested, ArcGIS will pick the right field type for you.
Unit Two – Attribute Tables 16 Editing Tables Entering Edit Mode ► Use the selection in the Tools Menu or Editor Bar appears here… ► Right-click anywhere in the window margins & pick “Editor” But can be “docked ” here. ► Use the Edit Icon or 1. Add the “Edit Toolbar”. 2. CLOSE TABLES THAT YOU WANT TO EDIT FIRST! 3. Select E DITOR M ENU
Unit Two – Attribute Tables 17 Editing Tables Changing Attribute Values Now that you’re in Edit Mode: What do you want to do? Change one or two values? Create new values that are calculated from existing ones? Change values in a set of records that are all related by common attribute value? Add a field? Delete a field? ► Edit Cells ► Calculator ► Selection ► Get out of Edit Mode white=editable pencil=edit mode
Unit Two – Attribute Tables 18 Editing Tables Changing Attribute Values ► Edit Cells ► Calculator ► Selection To edit single values, just put the cursor in the cell, and type. To calculate based on other values in the table, right-click the header, select C ALCULATE V ALUES. and enter a formula. With no selected records: formula calculates how many toes for every record.....in this case there is one selected record so the formula calculates only for that record. BE CAREFUL WHAT IS SELECTED!!
Unit Two – Attribute Tables 19 Your turn… Chapter 2: Step 10 through END