[Qgis-developer] point displacement renderer plugin

[Andreas Neumann]

> Another use to this type of methodology I saw in use recently is when
> working with line layers that are road networks. Sometimes you need
> mulitple parrallel lines of differing colors for some segments. Think of
> subway, bus or other transit maps where several lines share part of
> their routes and you want to show them all together.
>
>   
right - but this is an entirely different problem than the 
point-displacement render for point symbols that simply places points on 
a circle around the original center point.

What you describe above is more complex where you'd also want your 
bus-lines to have minimal intersections - a problem that is today 
typically still solved by human brains instead of computers ...
> An alternative visual to the one you have that might also be useful
> would be a clustering algorithm that combines overlapping or neighboring
> points into one symbol that automatically scales in size based on the
> number aggregated.
>   
right - but how would you display different attributes then? It would 
probably work for one attribute but would be more complicated for two or 
more attributes.

In our case we want to display both language and sex (male/female). 
Combining that into one shape would be problematic.

Quite some interesting problems though ...

Andreas