Convert lines to areas
Q: Is there a way to construct a vector polygon map from closed line rings?
A: Yes, to convert a lines map into an area map, do:
Requirement: the line rings must be closed.
- run to convert from line type to boundary type
- run to add missing centroids to closed boundaries
v.type input=map_l output=map_b type=line,boundary v.centroids input=map_b output=map_polygons