You can set the Primary offset distance between the line feature and the label by entering a value and choosing the type of units from the drop-down list. This offset can be measured from the geometry of the feature or from the feature symbology boundary. You can also constrain the placement of the label to a specific side of the line.
You can add a Secondary offset distance, which will be used if the label is unplaced after applying the Primary offset distance. This placement allows you to set a minimum and maximum offset value instead of an actual distance and places the label horizontal to the line feature.
You can control the location of a label along a line for all the placement styles. You can use the default setting, Best position, or you can specify a label position relative to the end of a line. A variety of measurement options are also available for offsetting labels along a line.
The Maplex Label Engine has a series of parameters for offsets along the line; using them together, you can control where on the line a label is placed. When using the Regular placement style and the Street address placement style you have the option to use only the visible feature geometry when placing labels.
You can place the label at the midpoint of a line:
- Position label—Along line from start
- Measured to—Center of label
- Distance—50 percent
Or you can place the label at a specified location:
- Position label—Along line from end
- Measured to—Nearest side of label
- Distance—5 mm
Offset a label from a line
For each of the Maplex Label Engine offset styles (Offset horizontal, Offset straight, Offset curved, and Offset perpendicular), you can control how far a label is from the line feature, determine whether the offset is measured from the feature geometry or the feature symbology boundary, and constrain the side of the feature on which the label is placed. You can set a preferred label offset distance from the line, measured in map units or page units (millimeters, inches, or points). You can also set a secondary offset that places the label horizontal to the feature. This label offset requires minimum and maximum values for the offset range.
You can constrain the side of a feature on which the label is placed using the Constrain offset drop-down list. The options are as follows:
- No constraint—Places the label on either side of the feature. The default location is always above the line, but if the label engine can't place the label above the line, it attempts to place it below the line.
- Above line—Places the label above the line based on feature orientation to the page.
- Below line—Places the label below the line based on feature orientation to the page.
- Left of line—Places the label on the left side of the line based on the inherent direction of the feature.
- Right of line—Places the label on the right side of the line based on the inherent direction of the feature.
The following image shows the ferry line labels placed with an offset of five points and no constraint:
Note:
The Constrain offset parameter is unavailable if the Street placement style is used for a particular label class.
Note:
If labeling with the Regular placement style, you can use the Allow stacked labels to straddle lines parameter. This parameter allows stacked labels to place on either side of the line feature when it is not possible to place offset on one side.
- Ensure that the Maplex Label Engine is enabled.
- In the Labeling pane, click Position and click the Position tab
. - Expand Placement.
- Optionally, if you are using the Regular placement style and either the Offset straight or Offset curved positions, check the Allow stacked labels to straddle lines check box.
- Specify a primary offset distance to offset the labels from the lines, and select an offset constraint.
Label offset parameters apply only to the label positions: Offset horizontal, Offset straight, Offset curved, and Offset perpendicular.
- Optionally, check the Measure offset from feature geometry check box.
- Optionally, check the May place label at secondary offset check box and specify Minimum offset and Maximum offset values.
The units are the same as those for the Primary offset value. This allows the label to be placed horizontally at the secondary offset if needed.
Offset a label along a line
The default setting is Best position. When this is selected, the Maplex Label Engine finds an available location somewhere along the line (the default location is toward the center of the line) to place the label. The options are as follows:
- Best position—Finds the closest available location to the midpoint of the line.
- Before start of line—Places the label at a specified distance before the starting point of the line. The starting point of a line is determined using one of two methods. If the Use line direction option is checked, the starting point is determined based on the order of the coordinates in the line feature. If it is not checked, the leftmost end node of a line relative to the map page is the start of the line.
- Along line from start—Places the label at a specified distance after the starting point of the line. The starting point of a line is determined using one of two methods. If the Use line direction option is checked, the starting point is determined based on the order of the coordinates in the line feature. If it is not checked, the leftmost end node of a line relative to the map page is the start of the line.
- Along line from end—Places the label at a specified distance before the ending point of the line. The ending point of a line is determined using one of two methods. If the Use line direction option is checked, the ending point is determined based on the order of the coordinates in the line feature. If it is not checked, the rightmost end node of a line relative to the map page is the end of the line.
- After end of line—Places the label at a specified distance after the ending point of the line. The ending point of a line is determined using one of two methods. If the Use line direction option is checked, the ending point is determined based on the order of the coordinates in the line feature. If it is not checked, the rightmost end node of a line relative to the map page is the end of the line.
Measure along clipped feature geometry
The Measure along clipped feature geometry option is available with the Regular placement style and the Street address placement style. When it is checked, the feature geometry visible in the map is used to place the label. If it is unchecked, the entire feature geometry is used.
Measure to
You can control which part of the label is measured to when a label offset distance is applied. The Measure to control sets an anchor point in the label that is used to place the label along the line.
- Center of label—Measures from the middle of the label.
- Nearest side of label—Sets the anchor point to the edge of the label nearest to the feature. If no offset distances are specified, the label tends to extend beyond the feature.
- Farthest side of label—Sets the anchor point to the edge of the label farthest from the feature. If no offset distances are specified, the label tends to lie on the feature.
Distance
The Distance parameter controls how far a label is placed from the start or end point of a line feature.
You can measure in map units or page units (millimeters, inches, or points), or a percentage of the line length. Percent is useful when you want to place a label at a specific location on the line but the lines vary in length. For example, to place all labels along the first quarter of a line, enter a distance of 25 and choose Percent for the units.
Tolerance (+/-)
The Tolerance parameter gives the label some freedom to move along the line. A Tolerance value of 0 specifies that the label should only be placed at the distance entered in the Distance edit box. The tolerance units are the same as the distance units.
Use line direction
When the Use line direction option is checked, the order of the coordinates in the line feature determines the start and end points of a line. When it is not checked, the start point is the leftmost end node of the line and the endpoint is the rightmost end node of the line, relative to the map page.
Example
The following image shows the ferry lines labeled 40 points from the end of the line.
- Ensure that the Maplex Label Engine is enabled.
- Ensure that List By Labeling is the active method of displaying the Contents pane. Click the List By Labeling tab
. - Choose a label class in the Contents pane and click the Labeling tab.
- On the Labeling tab, in the Label Placement group, click Label Placement Properties
. - In the Labeling pane, click Position and click the Position tab .
- Expand Placement.
- Click the Offset along line drop-down menu and choose a position along the line where you want labels to be placed.
Optionally, check the Measure along clipped feature geometry check box.
- Click the Measure to drop-down menu and choose the position on the label to which the offset should be measured.
- Specify the distance that the label should be offset along the line and the measurement units (map units or page units—millimeters, inches, or points, or percent).
- Optionally, specify a Tolerance up to which the label may vary from the offset distance you set.
A tolerance value of 0 indicates that the label must be placed at exactly the specified distance. Larger values allow the label to be moved along the line in case of conflicts.
- Optionally, check Use line direction.
This uses the order of the coordinates in the line feature to identify the direction of the line. When this is unchecked, the leftmost end node of the line is considered the start of the line.