- Mapping with ArcGIS Pro
- Amy Rock Ryan Malhoski
- 483字
- 2025-02-28 12:55:55
Symbolizing multiple values
Sometimes, we want to be able to symbolize features in a layer differently. We'll do this in more detail in future chapters, but for now, we just want to symbolize the United States so that it will stand out against the other countries for a locator map:
- Switch to the North America Map tab. This is going to become our locator map in the final layout. It may look a little strange right now, but we'll fix that.
- As we did with the US Counties map, let's rename the map layer to something more meaningful. Since we're going to be zooming in to focus on North America, name it North America. In this map, you will be shading the United States a medium-gray color, while leaving the other states white. This step is a bit more complicated than the previous step, as opening the Symbology from the Contents pane changes the symbol properties for all symbols.
- If the Symbology pane is still open, click on the Cntry_NAmerica layer name. Otherwise, click the symbol first to open the pane, then click the layer name to launch the Symbology pane to a different function than previously. (You can also reach this option by clicking the back arrow at the top of the pane.)
- In the Symbology drop-down menu, select Unique Values.
- Change the value field to CNTRY_NAME. Since this is a long list, you'll get a message that there are more than 100 unique values. Select No, since we don't want to generate the full list of unique values at this time:
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Figure 2.12: Generating unique values
At the bottom of the pane, a partial list of countries appears.
- Click the More button and select Remove all. This will clear out the list and leave only the <all other values> option.
- Click the plus symbol (+) over this pane (or click More again) to Add values. The pane will switch to the list of values. You may see the message about adding all values again; say Yes this time.
- Scroll to the United States and select it by clicking on it once, and click the OK button:
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Figure 2.13: Selecting a value from the list
Your Symbology window will now contain <all other values> and the United States:
- Click the box next to United States to open the Symbology. Change the Fill Color to gray 50% (hover the mouse over a color for a second or two, and the color name will appear in a pop-up box) and the Outline color to Black. Click Apply to commit changes and click the back button at the top of the pane to return to the previous screen.
- Repeat this step for <all other values>, but set the Fill Color to gray 10% and the Outline color to Black.
Close the Symbology pane. Your map should appear as follows:
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Figure 2.14: The North America map