Introduction High grade of user...

Introduction

High grade of user interactivity is a general requirement for maps designed to support "spatial thinking," i.e., hypothesis generation, data analysis, and decision making (MacEachren 1994; MacEachren and Kraak 1997) lately a number of software packages enabling user interaction with map displays have been created. Examples include:

* A dynamic link between maps and other images of graphical displays through "brushing;" ends selected in one of the displays are simultaneously highlighted in all of them (MacDougall 1992; Symanzik et al. 1996; Dyke 1997);

* Tools for changing, in real time, parameters of conventional cartographic orderly dispositions such as classes in