Exercise 3: Using the Legend Editor and Labeling
In this exercise, you will use the Legend Editor to create thematic maps using different legend types and classification methods, and you will learn how to label.
Step 1 – Start ArcView and open a project
If necessary, start ArcView. From the File menu, choose Open Project. Double-click the directory folders and navigate to c:\esritrn\arcview\wiscexer. Open the project wiscexer3.apr by clicking on the project name, then clicking OK.
Step 2 – Change the symbol color and legend type
When the project opens, the Project Window appears with two views in it. Open the Winnebago Wetlands view by double-clicking on it.
When you add a theme to a view, ArcView assigns a randomly selected color to all features. First, you will change the default color using the Legend Editor.
To open the Legend Editor, double-click on the Wetlands theme in the Table of Contents. The Legend Editor displays.
The Theme dropdown list shows the name of the active theme: Wetlands. The Legend Type dropdown list displays the default legend type: Single Symbol.
To change the symbol for the Wetlands theme, double-click on the Symbol rectangle.
The Fill Palette displays.
Click the Color Palette button at the top of the Fill Palette to switch to the Color Palette.
Scroll through the colors shown in the Color Palette and choose a different color by clicking on it. Close the Color Palette.
Click Apply in the Legend Editor to apply your color change to the theme.
ArcView redraws the theme using the new color. (You may need to move the Legend Editor out of the way so you can see the map display better.)
Next you will display the Wetlands based on their class names.
In the Legend Editor, change the Legend Type to Unique Value. In the Values Field dropdown list, scroll down and select Class. (Class is a field in the theme table that contains the types of all the Wetlands.)
The Legend Editor lists each class name along with a unique symbol from the Bountiful Harvest (default) color scheme.
To change the color scheme, click on the Color Schemes dropdown list and choose Minerals, then click Apply. Close the Legend Editor.
Each wetland class is now symbolized with a mineral color.
Note: If the Table of Contents is not wide enough to display the entire legend, you can make it wider by making the view active, then moving the cursor over the line that separates the scroll bar from the display area and dragging the line to the right.
Step 3 – Classify number of dams using natural breaks
Next, you will experiment with different ways to classify and display dam data. But first, you need to open the Wisconsin Dams view.
From the Window menu, choose wiscexer3.apr to open the project window. Double-click on the view called Wisconsin Dams.
This view contains one theme called Counties. The Counties theme shows all the counties in Wisconsin, and contains information about the number of dams within each county.
Double-click the Counties theme to invoke the Legend Editor. Change the Legend Type to Graduated Color and the Classification Field to Dams.
ArcView divides the values in the Dams field into five classes using the natural breaks classification method (default), and the red monochromatic color ramp (default). A color ramp is a range of colors used on a map to show ranking or order among classes. The natural breaks classification method creates classes from clusters of values.
To select a different color ramp, click on the Color Ramps dropdown list, then scroll down and choose Cyan monochromatic. Click Apply.
The Counties are displayed according to the number of dams in each using graduated shades of cyan. Lighter counties have fewer dams; darker counties have more.
You can also customize the number of classes and the value ranges. For example, let’s say you want one more class that will show all the counties with over 150 dams.
In the Legend Editor, click the add class button (plus sign) to add another class. (The X button deletes any highlighted classes). Then, click in the empty value field, type 150 – 203 and press Enter. Change the values in the class above it from 119 – 203 to 119 – 149 and press Enter. Click on the Color Ramps dropdown list and choose Red monochromatic to apply a color scheme. Click Apply.
The view now shows that there are only two counties with over 150 dams.
Step 4 – Change the classification method, number of classes, and labels
In addition to changing the classification method, you can change the number of classes and the labels that display in the Table of Contents.
Make the Legend Editor the active window. Click the Classify button. Change the type to Quantile. The quantile method creates classes that have the same number of features in each class. Select 3 from the Number of classes dropdown list. Click OK.
Click Apply in the Legend Editor.
ArcView creates three new classes using the quantile method, which places an equal number of counties in each class.
Suppose you want to make your map easier to read by a general audience. Rather than having numeric values for dam density, you can label the three classes Low, Medium, and High.
In the Legend Editor, under the Label column, click on the first (top) value to highlight it, type Low, and press Enter. Notice that after you press Enter, the view does not change. (ArcView only updates the view when you press Apply.) With the second (middle) value highlighted, type Medium and press Enter. Now with the last value highlighted, type High and press Enter.
The Legend Editor should look like this:
Now press Apply to apply all your changes to the view.
ArcView redraws the view and updates the legend with your changes.
Step 5 – Label theme features
Theme features can be labeled with the values from any field in the theme table. There are two ways in ArcView to label features: interactively, and with Auto-label. First, you will label features interactively.
First, go back to the Winnebago Wetlands view. From the Window menu, select Winnebago Wetlands.
Before labeling, let’s make the uplands transparent so that the labels are easier to read.
Double click on the Wetlands theme to display the legend editor. Scroll down and double click on the Upland symbol. Click on the Paintbrush in the upper right corner to invoke the Color Palette. Choose the transparent symbol (box in the upper left corner marked with an X).
It is important to note that different aspects of the symbol can be changed using the color palette, including the foreground, background, and outline. Foreground and background are used when changing the different components of hatching patterns. The outline choice changes the color of polygon boundaries.
Close the Color Palette window and click Apply in the Legend Editor. Close the Legend Editor.
Suppose you want to know the wetland code for a particular polygon. This information can be displayed using the label tool.
Click the Theme Properties button to open the Theme Properties dialog box (or choose Properties… from the Theme menu).
Click the Text Labels icon to display the theme properties for labels.
The label field dropdown list displays the field whose values will be used to label features. In this instance, ArcView defaults to <none>. The text buttons in the middle of the dialog box show how the label will be positioned relative to the center of the feature. The Scale Labels check box determines whether or not label size will change as you zoom in or out on the view. By default, Scale Labels is turned on.
Click on the Label Field dropdown list and choose Wetcode. Click on the middle text button to change the label placement.
Click OK to set the label properties.
Before labeling features, you will set the font for the labels.
From the Window menu, choose Show Symbol Window. Click on the Font Palette button at the top of the Symbol window.
In the Font Palette, select the Arial font and set the Size to 14, then close the Font Palette.
Click on the Label tool, then click on any wetland polygon to label it.
There are a number of other tools for labeling interactively, including various text boxes and road labels.
Click on and hold the Label tool down and select the following text label:
Now click on any wetland polygon and drag the cursor a short distance.
You can also use Auto-label to label features automatically. With this method, ArcVeiw does most of the work, labeling all features (or selected features) in the active theme at once.
From the Edit menu, choose Select All Graphics. Then, from the edit menu, choose Delete Graphics.
When you auto-label features, ArcView places the labels so as to minimize the number of overlaps. To see how this works, you will zoom in on the view.
Click the Zoom in tool.
Draw a box around the upper left corner as shown and release the mouse button to zoom in.
Now, from the Theme menu, choose Auto-label to open the Auto-label dialog box.
Auto-labeling gives you some additional options that are not available from the Theme Properties dialog box. The Find Best Label Placements option (the default) minimizes the number of overlapping labels. The Allow Overlapping Labels option lets you decide whether to display those labels which do overlap. The Line Label Position Option is grayed-out because it applies only to line themes. The Label Only Features in View Extent option lets you label only those features that are visible in the view, rather than all features in the theme.
Click on the check box next to Allow Overlapping Labels, remove the check next to Remove Duplicates, and click on the check box next to Label Only Features in View Extent. Leave the other default options turned on.
Click OK to label the Wetlands theme.
ArcView does the best it can to avoid label overlaps, but at the specified text size (fourteen point), some conflicts occur. Labels that overlap other labels appear in bright green.
At this point, you have several options – you could simply remove the overlapping labels, or you could repeat the auto-label process using a smaller font. Alternatively, you could convert the overlapping (green) labels to match the other labels (black), then reposition them manually with the Pointer tool. You will choose the first option and remove the overlapping labels.
From the Theme menu, select Remove Overlapping Labels to remove the green labels from the view.
Click the Zoom to Full Extent button.
The view returns to its full extent. Notice that the text labels are scaled down (Scale Labels was turned on) and that only the upper left corner was labeled (Label Only Features in View Extent was also turned on).
Step 6 – Close the project
Click on the on the Project window to make it active (or select wiscexer3.apr from the Window menu). From the File menu, choose Close Project. Click No when asked if you want to save changes.
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Wisconsin ArcView Exercise #3 - 10/09/18