Releases all allocated memory space associated with a specified surface.

surf_id—(optional) (long) A valid ID for a gridded surface.

All—If nonzero, destroys all active surfaces. (Default: 0)

The value of surf_id is obtained from the Surf_id keyword in the GTGRID function or from the output of the GTINSTALLSURF function.

GTGRID provides access to a library of gridding routines prepared by Geophysical Techniques (GT), Inc. The GT libraries maintain an internal representation of generated grids and their attributes such as the faults, the bounding polygon, the spacing between nodes, the origin, and so on. The default behavior for the GTGRID function is to destroy (free the memory for) this internal GT surface representation after gridding is complete. Destroying this surface representation does not affect any PV-WAVE variables, but after a surface is destroyed, it can no longer be queried by functions such as GTGETVALUE and GTGETGRID.

If you unload the GTGRID option (GTGRID_UNLOAD), all of the active surfaces are destroyed.