GISCARTA's posts

Proportional symbols

A modern way to style Point layers based on multiple attributes.
This style is applicable to Point layers and refers to a display adjusted by several layer attributes. Here you can set the display of attributes in three categories:
  • By symbol
  • By color
  • By size
To do so, select the attribute for each category and the way it will be set: Unique values or Ranges.
User can also configure the values and styles manually.
For Text attributes, it is possible to automatically load all unique values by selecting the "Unique values" method and clicking the "Set" button.

For Numeric attributes, user can set ranges using the following methods:
  • Equal intervals is a method that will divide the range of values into equal-size classes. For example, three classes for the range of values from 0 to 300 will be created with the following ranges: 0 — 100, 101 — 200, 201 — 300.
  • Equal number (quantile) is a method that will split the range of values into classes equal to the number of objects within each class.
  • Natural Breaks (Jenks optimization) is a method that will split the range of values into classes, the differences between values within which will be maximal.
Finally usercan set the symbol style for each of the set values separately or apply the general settings to all values by clicking on the "Gears" icon next to the word Symbol. General settings include selecting a palette or fill, and setting the look and size of the symbol.

Also user can specify aliases for the Legend.
Proportional symbols can be used in almost all areas of activity, such as:
  • Environmental studies
  • Transport Analysis
  • Mining
  • Urban Planning
  • Construction
  • Student studies
  • Geology