Create Unique-values Map

Instructions for use

There are two ways to create a new Unique-values Map, one is to create it based on the fields in the template thematic map, and the other is to create a blank field to create a thematic map. provided templates include default, four-color, Land Use, boundary line and administrative region. Unique-values Map is made based on Thematic Map Template, which is not only convenient and fast to operate, but also easy to meet the needs of batch mapping. O as to realize the reuse of the thematic template. Blank thematic map refers to the creation of a thematic map not based on an empty field. The user can specify the Field expression by himself.

When using the Use Template, you need to ensure that the field expression of the thematic map exists. If the current layer does not exist in the thematic map field in the Thematic Map Template, "Expression does not exist, so the thematic map cannot be displayed" will pop up. Please specify the appropriate expression again. Prompt dialog box for. The user can Use Template Create Thematic Map after re-specifying the Field.

Operation steps

  1. In Layer Manager, select a Vector Layer for which you want to make a Unique-values Map.
  2. Right Click and select Create Thematic Map.. in the pop-up Context Menu, or select a Unique Values Map Templates in the Single Value group of the Thematic Map tab. A Unique-values Map is created.
  3. A Unique-values Map created based on the template style is automatically displayed as a theme layer in the Add to Current Map Window, and a theme layer is added accordingly in the Layer Manager.
  4. The Thematic Map Template of the system and the Thematic Map Template of the User Custom will appear under the drop-down menu of Template, which can be managed uniformly through the Template Manager. See: Manage Thematic Map Template ". .

Blank thematic map

On the Thematic Map tab, in the Single Values group, click Unique-values Map "Drop-down Button, and select the Blank option to create a Unique-values Map of blank fields based on the selected layer. In this case, the expression field of Unique-Values Map is empty. After the user sets the expression field, Unique-Values Map can be generated according to the field value. The blank thematic map is suitable for a large amount of data, which avoids the problem that the initialized fields do not meet the user's needs and need to be modified manually.

Precautions

  • After selecting a Create Template and a Unique-values Map, the Unique- values Map "window will pop up. This window displays the default setting information of the current thematic map, such as the Color Scheme of the Unique-Values Map and the list of all thematic values. On this basis, the user can reset the style of the thematic values. By modifying the default Unique-values Map, the effect of thematic map is more suitable for users' needs.
  • After closing the "Unique- values Map" "window, you can double-click the layer in the" Layer Manager "" or right click the layer, and select the "Modify Thematic Map" "to open the" Unique- values Map "" window to modify and set the parameters.
  • If there is a capping (intersection, coincidence) relationship between the objects of the Dataset, the generation of the four-color thematic map will fail; if there are complex faces (faces with sub-objects) in the Dataset, the generation of the four-color thematic map will fail.
  • When using the "four-color map" template to make thematic maps, first use four-color filling, if the four-color filling calculation fails, it will automatically change to five-color filling.

Related topics

Modifying the Unique-values Map