A gauge widget depicts the value of a certain attribute or a count of features as a percentage of a target value; for example, a gauge might depict the unemployment rate for a layer of United States counties with census information. The target value in this case would be 100.
In many cases, gauges are more informative when the highlight value depicted by the gauge is below or exceeds a threshold value; for example, a gauge that depicts fuel level might have a threshold of 10 percent, where the color of the gauge's graphic and value text is displayed in a different color when the value is below this threshold. This is useful for drawing your attention when the information depicted by the gauge reaches some critical level.
When a single feature serves as the data source, the value for the chosen field is shown in the widget. If more than one feature is used, such as when there are multiple selected features, a summary operation is performed on the field values. The aggregate can be any one of the following:
- The average value across the features
- The maximum of the values of all the features
- The minimum of the values of all the features
- The sum total of the values of all the features
In an emergency management scenario, you could configure a gauge widget to show the number of people who have had to relocate to an emergency shelter after an earthquake. In this gauge, the widget shows values below the target threshold in green, which occurs when there are fewer than 15,000 people total (a sum operation) in all of the area's shelter locations. The widget displays red if the total increases above that threshold value, which causes an alert to appear. The maximum number of people that can be accommodated in all shelters is 25,000.
- Click Edit, and click Edit Operation View.
- To create a new widget, click Widget, click Add Widget, choose the type of widget, and click OK. To update settings for an existing widget, click Settings , and click Configure on the widget's window.
- Click the Data Source drop-down arrow, and choose the item that will provide the data for the widget.
- In the Title box, type a title that will be displayed in the widget's window.
- In the Description box, type a caption that will be displayed below the widget.
- The display type specifies what type of information you intend to display in the gauge. Click the Display Type drop-down arrow and choose whether to display a statistic or a count.
- Click the Value Field drop-down arrow and choose the attribute field that will be displayed. Set the type of operation (sum, average, minimum, or maximum). These options do not apply when displaying a count.
- Click the Target Range tab to set the minimum, maximum, and threshold values. You can either type a constant value or when displaying a statistic, choose a field and use it instead. If you want to include a threshold, check Percentage to display the percentage of the target value represented by the attribute value.
- Check Raise alerts when minimized if you want the widget to display a notification that target values are met and the widget is minimized.
- Click the Appearance tab to set the style, label, and color of the gauge. If you have set up a threshold value, you can set different colors for when the value is below or equal to and above the threshold.
- When using a data source that represents a single feature, such as a selection in a list widget, click the Name Field drop-down arrow to set the field value that will be displayed above the widget.
- When you're satisfied with the preview, click OK to finish configuring the widget.