As of Surfer 18, Rectangles, Rounded Rectangles, and Ellipses have been treated as special vector objects in Surfer. Though they look like polygons, the internal structure of these objects has meant that it hasn't been possible to use these types of objects in typical processes using Polygons, such as Assign NoData and Grid Volume calculations. Now these objects are created as true Polygon objects, so you can use them in the following operations:

• Assign NoData
• Grid Volume
• Label objects using attributes
• Move/Copy objects to another layer or the Plot Document
• Drag and Drop between Base(vector) layers
• Duplicate

Updated December 2021