When bound labels are created from fields in a drawing, the labels may be thematically formatted based upon the values in the fields. The foreground color, border color, background color, size, style and rotation of a label may be controlled by a field.
If per-label formatting is turned on the thematic format specified will apply to all labels in the labels component using the default format. If per-label formatting is turned on, thematic formatting is not dynamically applied to labels using custom formats.
To thematically format a labels component:
1. Open the labels component, or click on a labels layer in a map.
2. In the Format toolbar , click on the display characteristic to be formatted. Choose the foreground color, border color background color, style or size. Rotation may also be controlled by a field.
3. In the pull-down choice menu that appears, choose Theme.
4. In the thematic Format dialog, choose the controlling Field to be used.
5. Choose the Method to be used to construct intervals. Equal Count, for example, will assign approximately the same number of objects to each interval.
6. Choose the number of Breaks between intervals. This specifies the number of intervals as well.
7. Change the Align to value if even numbers of tens, hundreds, thousands, etc, values are desired for intervals. Change the Range if the default entire range needs to be extended or contracted.
8. Press the Tally button to create the given number of intervals. If interval numbers different than those created by the Method are desired, double-click into the interval numbers to change them.
9. Either use a preset color palette or click into the interval color boxes in the Values pane to change colors to whatever range is desired. To use a palette, select it in the Palette box and press Apply to apply the preset to the intervals. Check the Preview box to try out different combinations and see how they look in the labels component without committing the changes.
10. When satisfied, press OK.
See the Thematic Formatting topic for a detailed discussion of controls in the Format dialog used for thematic formatting..
Suppose we have a bound labels component created for a parent drawing of cities in the US that has a Name field and a Population field for each city. Suppose the labels were created from the drawing using the Name field using the procedure set forth in the Creating Labels from Fields topic.
In the illustration above we see the labels in a layer above a background map. The view is zoomed into a region within the great state of Texas. We would like to change the formatting of each label based upon the Population field. We'll begin by changing the size, so that labels for cities with larger population will be shown in a larger font.
In the format toolbar, click on the size button.
In the pull-down menu that appears, choose Theme.
Within the Format dialog that appears, choose the Population field as the controlling field. We'll use the Equal Count method so that there will be approximately the same number of labels of each size. To round off the interval values, we'll choose 4 as the number of digits for Align to and then choose Tally to recompute intervals to even 10,000 values.
On the right side of the Values pane are two columns of numbers. The column of numbers more to the left shows the number of objects in each interval and the column more to the right shows the current value of font size for each interval. Note that the rightmost number for each interval is 8, the default font size. By double clicking on each font size value we can change it.
For example, here we have changed the font sizes from all 8's to a range from 6 to 14. Press OK.
The result is that labels for cities with larger population will be shown in larger font sizes.
We can also change the label style, if desired. To do so, click on the label style button in the format toolbar and choose Theme.
Once again, we will choose Population as the controlling field and Equal Count as the method. We will also Align to 4 digits and press Tally to round off the intervals to the nearest 10,000.
We will change the style for only one interval, the largest, by double clicking on the style sample and choosing one with a drop shadow effect in background color. Press OK.
The result is that the largest labels are now shown in a drop shadow style.
To illustrate a change in foreground color, we can click on the foreground color button in the format toolbar and choose Theme.
As before, we will choose Population as the controlling field and Equal Count as the method. We will also Align to 4 digits and press Tally to round off the intervals to the nearest 10,000. We will choose the Spectrum palette and apply it to the intervals to color them automatically.
The result is that labels are thematically colored based upon the size of the controlling Population field for each label. In this particular case the effect is not very sophisticated given the garishness of the palette used, but it does illustrate the process of thematically formatting label foreground color.
Note that in the above example we used the same field and the same method with the same number of intervals to format size, style and foreground color. It is very easy to use thematic formatting to vary too many variables at once and so create a confusing presentation. See the comments in the Thematic Formatting Example topic for advice on avoiding overly complex, and thus incomprehensible, presentations.
Turning Layers Off/On by Zoom
View - Properties - Zooms