5
votes
3answers
223 views

Should I use a discrete or continuous scale for coloring a chloropleth?

I am making a choropleth for an upcoming local race using D3. There are two candidates running for an election. For any given polygon on my map, if the red candidate has more votes, the color should ...
1
vote
0answers
28 views

QGIS rule-based point style responding to number of co-located objects?

I am mapping the geolocated location information for 5.5k Twitter profiles as point data. Many of them have the same location ie "London, UK" meaning that they return identical coordinates. On the map ...
14
votes
3answers
333 views

Is it possible to use symbols instead of colours to visualise raster cell values?

I have a raster image (GeoTIFF) with integer values. I know how to visualise raster values in QGIS using colormaps or similar, but I would like to assign symbols to each colour value instead - just ...
8
votes
3answers
470 views

How to present three spatial variables in one map? [closed]

I want to assign 3 category of variables in a single map. In other words, I have to produce a cartographic visualization of the damage including a legend listing: damaged surface area in the ...
6
votes
3answers
910 views

How to normalize choropleth maps of census information?

I'm trying to improve on the census-based maps on this site, which shows census values at 5 scales from Collection Districts through to State. Currently the maps show whole numbers (eg total ...
10
votes
7answers
590 views

What is the point of standard symbology?

There are several questions on the site asking for standard symbology to represent markers of specific types of objects (i.e. Power Distribution, Crime Mapping, Emergency Symbols, Lakes). What is the ...
25
votes
4answers
3k views

Curved point-to-point “route maps”

I have recently been looking at airlines web pages that display their routes departing a certain city to all other cities they service. I would like to be able to create similar curved routes between ...
23
votes
5answers
2k views

Are there any international standards for map symbology?

We are going to let our users add points, polylines and polygons to a map. Are there any international standards for map symbology? For example for emergency symbols?