Creating a Grid Surface Thematic Map - MapInfo_Pro - 2023

To create a Grid Surface thematic map:

1. Click on a Map window containing the layer you wish to create the theme for.
2. On the MAP tab, in the Content group, click Add Theme to open the Create Thematic Map - Step 1 of 3 wizard panel.
3. Click Grid.

   The inflection colors for the templates are displayed in the Preview section of the dialog box.

4. Choose a grid template from the Grid Template list box.
5. Click Next to open the Create Thematic Map - Step 2 of 3 wizard panel.
6. Select a table and field:
   • Table - Select the table that you want to create the thematic map on. The list contains all of the open, mappable tables.
   • Field - Only numeric data columns display; date columns do not display.
   • Ignore Zeroes or Blanks - Check this to treat zeroes or blanks as NULL values. In the case of grids, we do not interpolate points with a zero value if this box is checked.
   • Grid Options - These options display only if the theme being created is a grid theme.
7. Select a table of boundaries to clip against:
   • Clip Table - Choose a table of regions to clip the grid against. Defaults to none. Grid cells will be written if the cell falls within the regions of the selected table.
   • Grid File Name - Specify the directory and name of the new grid file that will be created. By default the grid will be named according to the source table and field. The new grid file will be saved in the directory specified by the New Grids (on the PRO tab, click Options, and Directories.
   • Browse - Click to display a directory picker; select a directory in which to place the new grid file. If you click OK in the directory picker, the directory in the Grid File Name edit control will be updated.
8. Click Next. The Create Thematic Map - Step 3 of 3 wizard panel opens. The following options apply specifically to grid surface thematic maps:
   • Settings - Choose Settings to display the IDW Interpolator Settings dialog box. This dialog box lets you change settings for the interpolator selected in the Interpolator combo box.
   • Styles - Displays a dialog box where color inflections and adjustment are specified.
   • Legend - Edit the map legend title, subtitle, and range labels.
   • Interpolator - Disabled when you are modifying an existing grid that does not have interpolation settings. Only visible when building grid surface themes.
   • Template - The buttons in the Templates group enable you to specify a name for a template, save the thematic map as a template, and when modifying an existing theme merge the thematic map with another template.
   • Save As - The grid template file will be saved with the .thm extension.
   • Merge - Select this option to display the Merge Template dialog box. This dialog box displays only themes of the same type as the theme you are merging. The Merge button is enabled only when you are modifying an existing theme, not when you are creating a theme.