topic Re: Very basic thematic Map in ArcGIS API for Flex Questions

Very basic thematic Map

RichardSchenkel — Fri, 10 Jun 2011 20:04:03 GMT

I think this is a very easy function. But I have been jumping around all over the ESRI site trying to find a solution.

I would like to create very basic thematic maps. I have seen these maps referred to as "density maps" and "Heat Maps". I have data on continents,country, state/region, city, etc. So when you view the map the areas with the higher data values have deeper colors.

I don't need any level of detail on the maps (e.g. rivers, topography, capitals, streets). But just have it colored according to its data value.

Are there any examples of this?

Re: Very basic thematic Map

MattJensen — Sun, 12 Jun 2011 10:45:58 GMT

I have done some basic mapping based on US Census Data in the Chesapeake Bay Watershed here http://204.236.161.112/_CBWS03.html I am currently trying to load the legends for each layer.

I think that Action Script can create a "continuous graduated color" map if you query an xml files a specific attribute on a published map on the fly (but that is way, way above my level). What I did was in ArcGIS Desktop I created a map based on an attribute adjusted the colors and ranges, then published the map as a map service.

I would look at http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//00s50000001r000000.htm

Hope this helped
Titoqan

Re: Very basic thematic Map

MarkSchenkel — Sun, 12 Jun 2011 14:53:47 GMT

Thank you for your repsonse. This seems to be on the right track.

I have created a service which integrates with the Google Analytics API. Within Google Analytics you can do geographical heat maps to visualize where your visitors are coming from. I would like to simulate these maps.

As an example consider a map of the U.S. I would pass color parameters for each state. The key though is this needs to be done realtime.

Can ArcGIS do this?

Re: Very basic thematic Map

ZahidChaudhry — Sun, 12 Jun 2011 15:15:13 GMT

I think what you are trying to do can be done easily with layer definition query using a feature layer..
this link will help you to do that
http://help.arcgis.com/en/webapi/flex/apiref/com/esri/ags/layers/FeatureLayer.html
here is a sample from resource center
http://help.arcgis.com/en/webapi/flex/samples/index.html?sample=FeatureLayerBasedOnMapServerLayer
Although, this sample is showing class renderer, but you can use other options too like definition expression dynamically and change the color/display dynamically...