[R-sig-Geo] newbie questions

[Alex Mandel]

tom sgouros wrote:
> Dan Putler <dan.putler at sauder.ubc.ca> wrote:
> 
>> Tom,
>>
>> Er, what exactly is your data? Do you have data that is linked to zip
>> codes and you want to do a "thematic" (choropleth) map of the data? Do
>> you have point data (say a lat/lon values), and want to plot the points?
>> Given what you've said, hard to figure out how to get you going in the
>> right direction.
> 
> The data is mostly from past elections, so it's vote totals or
> demographic data within some district.
> 
> Google tells me that choropleth is the name of precisely the kind of
> thing I'm trying to make, thank you for expanding my vocabulary today.
> 
> Is there a name for the bar graph kind of thing?  (Here's an example:
> http://www.turbosquid.com/FullPreview/Index.cfm/ID/346428 )
> 
> Thank you,
> 
>  -tom
> 

It sounds like what you need is a base map of districts from whatever
governmental agency has jurisdiction(Fed, State or County). It will
likely come as a shapefile or other similar format as polygons. You will
then Join your election data to this spatial data set based on some sort
of shared ID key that exists in both.

This could be done easily in either QGIS or R. I would leave GRASS out
of the discussion for now if we're just talking about making a map and
bring it back in if you start wanting to analyze the spatial
relationship between your data and other data sets.

FYI, there are both R and GRASS plugins for QGIS which I think is a good
tool for getting started with GIS.

Most people would call that link you sent a 3D visualization, there are
lots of ways to do that in GRASS(nviz), R and even Google Earth (fairly
common).

Alex