A classed post map is a map where symbols are posted at specific XY point locations, and the symbols are divided into bins by a third numeric value. Each bin has its own specific symbol properties. For example, you could have all points with a low concentration value colored blue square, all points with a medium concentration value a green triangle, and all points with a high concentration value a red circle.
To create a classed post map:
- Create a data file with X, Y and Z columns. The Z column is the column that is used to class the points. It must be numeric.
- In the Surfer plot window, click Home | New Map | Post | Classed Post.
- Select the data file and click Open.
- In the Contents window, select the Classed Post layer, and in the Properties window click the General tab.
- Verify the X coordinates, Y coordinates and Z coordinates columns are specified correctly.
- To edit the properties for each class (numeric range and symbol properties), click the Classes tab in the Properties window and click the Edit Classes button.
- There are many options to set the class properties (e.g. double click on a specific symbol to edit only that symbol’s properties, or click on the Symbol button to set global symbol properties or specific a color gradient for the symbols).
- When finished editing, click OK to apply the changes.
Use classed post maps to divide symbols into classes by a numeric value, and apply specific drawing properties for each class.
Updated September 4, 2020