Label Thematic Map Advanced Options

The Advanced option in the Thematic Map panel is primarily used to control the display of labels in the current label thematic map.

Label Alongline

The parameters in the label alongline area are used to control the display effects of labels in a line label thematic map. The involved parameter descriptions are as follows:

Fixed Text Angle: If this checkbox is selected, the text in the label objects within the label thematic map will always maintain a vertical orientation.
Remove Duplicate Labels: After selecting this checkbox, the complex line object will be preprocessed, treating multiple connected objects with the same name as a single object for labeling. If not selected, these objects will be labeled separately.

Figure: Remove Duplicate Labels Not Selected Figure: Remove Duplicate Labels Selected
Notes:
- The Remove Duplicate Labels setting is invalid when generating vector tiles.
- If the associated property field of a join table is used in the label expression, the Remove Duplicate Labels setting is invalid.
Alongline Mode: To ensure good display effects for label thematic maps in different usage scenarios, the application provides normal mode and river mode.
- Normal Mode: Suitable for labeling point and region data, such as place names or attribute values.
- River Mode: Suitable for labeling river line data. In this mode, labels can be evenly distributed along the river, avoiding situations where river labels appear too small. The text direction is reasonable, and no labels are placed at positions with many or large bends, resulting in uniform and aesthetically pleasing river labeling.
Alongline Display Direction: Used to set the direction of the text label along the line. The application system provides five methods:
- Along the Normal of the Line: Labels are placed from the start point to the end point along the line direction.
- Top to Bottom, Left to Right: For vertical lines, labels display from top to bottom; for horizontal lines, labels display from left to right.
- Top to Bottom, Right to Left: For vertical lines, labels display from top to bottom; for horizontal lines, labels display from right to left.
- Bottom to Top, Left to Right: For vertical lines, labels display from bottom to top; for horizontal lines, labels display from left to right.
- Bottom to Top, Right to Left: For vertical lines, labels display from bottom to top; for horizontal lines, labels display from right to left.
Notes:
- When using this function, the line's orientation (horizontal or vertical) is automatically determined. The criterion: Connect the start and end points of the line. If the angle between this line and the horizontal direction is less than 60 degrees, the line is considered horizontal; otherwise, it is vertical.
- If the Fixed Text Angle checkbox is selected, the setting of the drop-down button on the right side of the Alongline Display Direction control is invalid.
- If Alongline Display Direction is set first, then Fixed Text Angle is selected or Alongline Character Spacing is modified, character overlap may occur due to character spacing issues, causing some labels not to be displayed.
Alongline Character Spacing: Used to set the distance between characters in the label text, in multiples of the character height. The value range is [1,8]. For English words and numbers, spaces are used to determine whether it is a word or a number. For example, "SuperMap" and "12325" represent one word and one number, respectively. For "SuperMap" and "123 25", it represents "SuperMap", "123", and "25", totaling two words and two numbers. Spacing will be displayed at spaces according to the specified alongline character spacing.
Alongline Character Relative Angle: Sets the maximum angle between adjacent characters or letters to ensure the aesthetic quality of label alongline. The value range is [0,90]. A smaller angle tolerance results in more compact labels, but labeling may be impossible at positions with high curvature. A larger angle tolerance allows labeling even at positions with high curvature, but the aesthetic quality of label alongline decreases. Therefore, considering map aesthetics, it is recommended to first calculate a suitable angle value. The relative angle between characters or letters in label alongline is shown in the following figure:
Cycle Spacing Unit: Used to set the unit for the cycle spacing value in label alongline. Click the drop-down button on the right, and choose Unit or 0.1mm from the drop-down menu as the cycle spacing unit. 0.1mm means the cycle spacing of labels is in units of 0.1mm; Unit means the set label cycle spacing is consistent with the unit of the map's coordinate system.
Alongline Cycle Spacing: When a line object is too long, it can be labeled repeatedly at intervals. The text box on the right side of this control is used to set the distance for repeated labeling. Note that the cycle length set here refers to the distance from the end of the previous label text to the start of the next label text. As shown in the following figure, labeling a section of railway with an alongline character spacing of 1x and an alongline cycle spacing of 100. The distance measured from the end of any label text to the start of the next label text is exactly one alongline cycle spacing, with a length of 100. The unit is consistent with the map's unit.
Drawing Type: Sets the drawing strategy for alongline drawing, providing five drawing methods:
- Compatible Draw: Starting from SuperMap GIS 8C(2017), the drawing strategy for alongline labeling was adjusted. If the thematic map was created with a previous version and you want to display the original thematic style, it is recommended to select the "Compatible Draw" option.
- Entire Draw: Draws the label as a whole, generally applied to label alongline with background labels.
- Split Draw: Splits and draws the words and letters within the label separately. Using split draw, the label will conform to the trend of the line being labeled.
- Entire Draw (for right-to-left reading text): Draws the label as a whole from right to left, suitable for text displayed from right to left, such as Arabic. When using this drawing method, the label font must be set to a Western font, such as Times New Roman, and the Alongline Display Direction must be set to Along the Normal of the Line; otherwise, the label's display effects may be incorrect under this drawing method.
- Split Draw (for right-to-left reading text): Splits and draws the text within the label, suitable for text displayed from right to left, such as Arabic. When using this drawing method, the label font must be set to a Western font, such as Times New Roman, and the Alongline Display Direction must be set to Along the Normal of the Line; otherwise, the label's display effects may be incorrect under this drawing method.
Show Overlapping Objects: Select this checkbox to show labels for overlapping objects, enhancing map readability.
Display Overlong Label: Used to control the display of labels whose length exceeds the line length. Select this checkbox to display labels whose length does not exceed a specified multiple of the line length, defaulting to 2 times the length of the labeled line object. If not selected, the maximum displayable label length is the length of the line object. For example, if a river line dataset contains many line objects with long names but short lengths, and this option is not selected when creating the label thematic map, these labels will not be displayed.
Preprocessing Complex Line: Select this checkbox, as shown in the figure below, to show labels at positions with high curvature and to show labels whose document length is greater than the labeled line segment.
Adapt Label Position: Select this checkbox, and the application can automatically choose a suitable position on the object for labeling, avoiding the situation where all labels are displayed at the object's center, causing overlap.
The Text Order is Consistent with the Line Direction: Specifies that the text display order of the label is consistent with the direction of the line object.

Label Length Settings

Overlong Processing Method: Used to set the display method for labels when the text is too long. The system provides four processing methods: Single Line Display, New Line (Hide the Newline Character), New Line (Show the Newline Character), and Omit. Specific descriptions are shown in the table below, where the newline character in the illustration is set to "-", and Single Line Text Count is set to 6, meaning that when the overlong processing method is set to New Line or Omit, both Chinese and Western characters display 6 characters. (In the Omit section of this table, Single Line Text Count is set to 5.)

Processing Method	Description	Illustration
Single Line Display	All text is displayed in a single line.
New Line (Hide the Newline Character)	Regardless of whether a newline character is set, line breaks occur according to Single Line Text Count. Text content longer than the given length is displayed on a new line, and no newline character is displayed.
New Line Display (Show Newline Character)	If a newline character is set for the text, line breaks occur at the newline character, and the newline character is displayed at the end of the previous line. If no newline character is set, line breaks occur according to Single Line Text Count, and text content longer than the given length is displayed on a new line.
Omit	Text content longer than the given length is replaced with an ellipsis for display. The given length is controlled by Single Line Text Count. For English characters, the system treats each letter as a unit, and overlong content is omitted and not displayed.

Notes:

If the label alongline function is set, this function does not take effect.
This method automatically adjusts the number of characters per line, trying to keep the number of characters in each line similar. Therefore, the number of characters displayed per line is less than or equal to the set Single Line Text Count. For English words and numbers, spaces are used to determine whether it is a word or a number, and each line will completely display an English word or number.

Specify Newline Character: Click the drop-down button on the right side of the control, select a symbol as the newline character, or enter a character or word in the text box to specify it as the newline character. Text labels will display on a new line at the newline character.
Single Line Text Count: The text box on the right side of the control is used to set the maximum number of characters displayed per line in the label object (text) (individual English letters, Chinese characters, spaces, etc., are all considered one character). If this length is exceeded, the content in the text will be displayed on a new line or the exceeding part will be omitted. For English words, if a word happens to need to be split across two lines at the line break position, the system will handle it specially and display the entire word on the previous line. This parameter only takes effect when Overlong Text Processing Method is set to Omit or New Line Display.
Label Position: Used to set the label position for polygon objects, supporting Horizontal Label and Straight Label.
Text Alignment: If the Overlong Processing Method for the text is set to New Line, you can set the text alignment. Supported alignments are: Center, Left Align, Right Align, and Distributed Alignment.
Multiple Lines Align Automatically After Avoiding: Select this checkbox, and the text after avoidance will be automatically aligned for display.
In-region Labels: When selected, labels are only displayed inside the polygon region.

Repeated Marking Avoidance Range

The repeated marking avoidance range is used to set the avoidance range for repeated labels within the same label layer in the X and Y directions. By setting this value, duplicate labels within the avoidance range can be removed. The entered values must be non-negative.

The unit of the repeated marking avoidance range is consistent with the unit of Label Offsets in the Properties tab. If the offset unit is in logical units (0.1mm), the buffer radius for repeated marking avoidance will also be in logical units (0.1mm). If the offset unit is in Unit, the set repeated marking avoidance range unit is consistent with the map's unit.

Landscape: According to the set avoidance range size, duplicate markings located within the horizontal tile range are filtered and not displayed.
Portrait: According to the set avoidance range size, duplicate markings located within the vertical tile range are filtered and not displayed.

Label Height Range

Maximum Text Height: When zooming in, if the font height of the label object's text exceeds the maximum value set here, the text height in the label object will no longer enlarge as the map zooms in.
Minimum Text Height: When zooming out, if the font height of the label object's text exceeds the minimum value set here, the text height in the label object will no longer shrink as the map zooms out.

Avoid Overlap Settings

Horizontal: According to the set tile range size, text located within the horizontal tile range is filtered and not displayed. The avoid overlap settings are consistent with the offset unit in the "Properties" tab. If the offset unit is "in units of 0.1mm", the buffer radius for text avoidance is in units of 0.1mm; if it is "consistent with the map distance unit", the unit of the set avoid overlap settings is consistent with the unit on the map.
Vertical: According to the set tile range size, text located within the vertical tile range is filtered and not displayed. If the offset unit is "in units of 0.1mm", the avoid overlap settings are in units of 0.1mm; if it is "consistent with the map distance unit", the unit of the set avoid overlap settings is consistent with the unit on the map.