A pictorial human computer interaction to query geographical data

This paper proposes an extension of the Pictorial Geographical Query Language GeoPQL, that allows the user to express queries pictorially. Topological and metrics operators are already presented in a previous work. This extension refers to queries in which the user uses concepts that the system implicitly interprets and transforms. In particular, the paper adds the oriented polyline to the classic three objects (point, polyline, and polygon) and defines a set of cardinal and positional operators. In order to maintain non-ambiguity in the query's visual representation, GeoPQL uses three different working spaces, the first for topological and metrics operators, the second for cardinal operators, and the third for positional operators