Superscript/Subscript

When making a Thematic Label Map, you can use Label expression to implement the function of labeling up and down. When the field of the Thematic Label Map is Text and the superscript and subscript are required in the text, the superscript and subscript can be displayed by using the expression meeting specific rules and the "Superscript/Subscript" function.

Currently, the Thematic Label Map types supporting the superscript and subscript functions are Uniform Label Thematic Map, Ranges Label Thematic Map and Label Matrix Thematic Map.

The superscript and subscript function is often used when the map is marked. For example, when the area is marked, the unit of the area needs to be marked: km2 . At this time, the superscript and subscript function needs to be used. The area of each administrative district shall be marked completely, and the unit shall be km2 . In the UDB Data source, Label expression is: Provinces _ R. AREA | | "km # + 2" or Provinces _ R. AREA | | 'km # + 2'; In the Oracle Data source, the Label expression is: Provinces _ R. AREA | | 'km # + 2'. The Provinces _ R. AREA field records the area value of each administrative area, which is a double-precision field. When labeling, the numeric field is converted to the text type, and then the area unit (km2 ) is connected for display. Note: The concatenation symbol for text in UDB or Oracle Datasource is "| |". The effect is shown in the following figure:

Label expression rule

In order to achieve the superscript and subscript effect, Label expression needs to be written according to certain rules:

  1. In a text expression containing superscripts and subscripts, # + indicates a superscript, #-indicates a subscript, and # = indicates splitting a string into two superscript and subscript parts.
  2. A text label that supports Label expression is set. If it starts with "# +", "#-", "# =", the entire string is output as it is.
  3. When # + or #-is encountered, the next string is treated as the superscript and subscript content, and the new string rule is used when # + or #-is encountered for the third time.
  4. In a text expression containing a superscript or subscript, two consecutive "# +" have the same effect as a "#-" and two consecutive "#-" have the same effect as a "# +".

Precautions

  • Alignment of labels with superscript and subscript can only be displayed as "upper-left corner" effect. Alignment of labels of texts without superscript and subscript is the same as that set in Text Style.
  • The text label with Rotation angle is not supported, and when the Rotation angle of the text label is not 0, the superscript and subscript function is invalid.
  • When the map has Rotation angle, the superscript and subscript text labels are set not to rotate with the rotation of the map.