[R-sig-Geo] mapping introduction

[Dylan Beaudette]

On Saturday 24 November 2007 02:04:17 pm Tom Sgouros wrote:

Hi Tom, sorry to hear that you haven't discovered what you were looking for 
yet. Here are some comments / suggestions.

> Hello all:
>
> I was referred to this list when I asked a question on the r-help list
> about mapping.  Unfortunately, I seem to be a little late to the party,
> and a couple of weeks of monitoring the traffic have left me no more
> enlightened than I was before, since it seems that the questions asked
> are generally at a level I haven't approached yet.

R is one of those applications which takes some time to get into. I have been 
a graduate student for a couple years now, and it took three attempts to get 
over the initial "activation energy" required for me to feel comfortable with 
R. That said, persistence was really the key factor in getting there. 

> I am an R user who wants to learn to make maps.  I have been using R to
> analyze data associated with cities and towns in my area, and would
> like to figure out how to get that data onto a map, but I'm having a
> hard time seeing where to begin.

Now that you are familiar with working in R, it might be a good idea to become 
familiar with basic GIS concepts. There are a number of open source tools 
which can be used for GIS work, and quite a large community in the form of 
mailing lists / IRC channels. There are a number of books which should be 
coming out in the next couple of months which cover the wide range of open 
source GIS software. 

> Assuming that I'm starting pretty much from zero, where can I start
> reading in order to learn what is possible?  (And what to use to achieve
> it.)

Most of what I have learned about spatial statistics in R has been from a 
collection of books on R, R newsletter articles, and misc. online tutorials. 
Here is a link to some tutorials which illustrate using GRASS and R:

http://casoilresource.lawr.ucdavis.edu/drupal/node/438 

> I'm also a little confused about whether people use R as a GIS stand-in,
> or whether they use some GIS package, and then use R as an adjunct.  If
> the latter, can anyone recommend GNU or other freeware GIS packages to
> learn about? 

Since *most* R operations occur in memory, GIS operations on large datasets 
are best done in a dedicated GIS app like GRASS. For most of my work GRASS, 
GMT, PostGIS, R, and Mapserver are a tough combination to beat. 

> How about books to learn about them with? 
>

See above suggestions. There should be two books out soon which are dedicated 
to opensource GIS applications- I would keep an eye out for these.

Cheers,

Dylan