In Surfer 16 and newer, you can calculate grid statistics for areas inside or outside a polygon or set of polygons:
- Click Grids | Info | Grid Info
- In the Grid Info dialog, choose a grid file to use as the Input Grid.
- Choose an input vector file or Base(vector) layer to use as the Polygon Boundary. It can either be a single polygon or a complex polygon.
- Specify whether you want the grid statistics calculated Inside, Outside, or as a Mixed polygon.
- Click OK to calculate the statistics. The results will be presented in the Grid Information Report.
Updated August 2019