2 Click the General tab, and in the Layer Name box, type Breast Cancer Deaths by County and then click OK. The layer name is now changed in the table of contents.
Change the boundary-layer fill color
To better see the counties for the Breast Cancer Deaths by County layer, you will want to change the color properties of both the county and the state layers. First, you will change the counties to a white fill color with a light-gray outline.
1 In the table of contents, click the layer symbol for Breast Cancer Deaths by County. The layer symbol is the rectangle below the layer name in the table of contents.
2 In the resulting Symbol Selector dialog box, click the Fill Color arrow.
3 In the color palette, click the Arctic White tile.
4 Click OK. On the map, the fill color of the layer changes to Arctic white.
Change the layer outline color
1 In the table of contents, click the layer symbol for Breast Cancer Deaths by County.
2 In the Symbol Selector dialog box, click the Outline Color arrow.
3 In the color palette, click the Gray 20% tile.
4 Click OK. On the map, the outline color of the layer changes to light gray.
Change the layer outline width
Because county and state boundaries share some of the same lines, it is useful to display the Breast Cancer Deaths by State layer using a Hollow fill and a dark, thick outline so you can see the county polygons above it.
1 In the table of contents, click the layer symbol for Breast Cancer Deaths by State.
2 In the Symbol Selector dialog box, click Hollow.
3 In the Outline Width box, type 1.25, and click OK. (See facing page.)
4 In the table of contents, drag the Breast Cancer Deaths by State layer so it is just above Breast Cancer Deaths by County. The resulting map is much easier to read. The layer names are self-descriptive, and it is easy to distinguish between the county and state outlines.
Drag a layer from the Catalog window into the table of contents
The Catalog window allows you to explore, maintain, and use GIS data through its many ArcCatalog utility functions. From Catalog, you will drag a map layer into the table of contents as an alternative method to add data.
1 Click Windows > Catalog.
2 In the Catalog window, browse through the Data folder to UnitedStates.gdb.
3 Drag USLakes from UnitedStates.gdb in the Catalog window to the top of the table of contents. If you get a warning about the coordinate system, click yes to “use this coordinate system anyway.” The map layers in the table of contents draw in order from the bottom up, so if you dropped USLakes at the bottom of the table of contents, the states would cover the lake features.
Remove a layer
1 In the table of contents, right-click USLakes and click Remove. This action removes a map layer from the map document, but it does not delete it from its storage location — in this case, the United States geodatabase.
YOUR TURN
From the Catalog window, add USRivers and USInterstates from the United States geodatabase. Practice changing the layer colors and outlines, drag the layers to the top and the bottom of the table of contents, and remove the layers when you are finished.
Use Auto Hide for the Catalog window
Notice that when you opened the Catalog window, it opened in pinned-open mode, which keeps the window open and handy for use but also covers part of your map. The Auto Hide feature of this application window, along with other application windows such as the Table Of Contents and Search windows, keeps the windows available for immediate use but hides them between uses so that you have more room for your map.
1 Click the Auto Hide button at the top of the Catalog window. The window closes but leaves a Catalog button on the right side of the ArcMap window
2 Click the Catalog button. The Catalog window opens.
Next, you will simulate completing a Catalog task by clicking the map document. The window will automatically hide.
3 Click any place on the map or in the table of contents.
You can pin the window open again, which you will do next.
4 Click the Catalog button and then the Unpinned Auto Hide button . This action pins the Catalog window open until you click the pin again to automatically hide or close the window. Try clicking the map or the table of contents to see the Catalog window remain open.
5 Close the Catalog window.
Use relative paths
When you add a layer to a map, ArcMap stores the path to its location in the map document. When you open a map, ArcMap locates the layer data it needs by using this stored path. If ArcMap cannot find the data for a layer, the layer still appears in the ArcMap table of contents, but of course it does not appear on the map. Instead, ArcMap places a red exclamation mark (!) next to the layer name to indicate that its path needs repair. You can view information about the data source for a layer and repair it by clicking the Source tab in the Layer Properties dialog box.
Paths can be absolute or relative. An example of an absolute path is C:\EsriPress\GISTHealth\Data\UnitedStates.gdb\USLakes. To share map documents saved with absolute paths, everyone who uses the map must have exactly the same paths to map layers on their computer. That is why rather than absolute paths, the relative path option is favored.
Relative paths in a map specify the location of the layers relative to the current location on the disk of the map document (.mxd file). Because relative paths do not contain drive letter names, the map and its associated data can point to the same directory structure, regardless of the drive or folder in which the map resides. If a project is moved to a new drive, ArcMap will still be able to find the maps and their data by traversing the relative paths.
1 On the Menu bar, click File > Map Document Properties. Notice that the check box is selected to “Store relative pathnames to data sources.” This option should be set for all map documents