I use postgreSQL.8.4.2 and don't have postGIS installed. I have a geometric type polygon and I know that it is possible to determine if a point it is inside or not of this polygon, using anything like that: select polygon('(-23.5672,-46.6510),(-23.5670,-46.65095),(-23.5672,-46.6508),(-23.5672,-46.6510)') @> point('-23.567534,-46.64942')
The question: Anyone knows an algorithm or have ideas how to determine if a point it is inside an area constructed by geometric type path expanded for a known distance? Graphically:
the path x=========x=======x the path expanded by a distance
| | A | | | | -------x=========x=======x------- C | | | B | | |
the points A and B are inside and the point C are outside .
Suggestions are welcome. Thanks in advance, Josi Perez
