[R-sig-Geo] Open source GIS and R

[Barry Rowlingson]

On Fri, Sep 17, 2010 at 12:13 PM, Manuel Spínola <mspinola10 at gmail.com> wrote:
>  Dear list members,
>
> I am an ecologist interested in spatial and landscape ecology and a user of
> ArcView 3.3 with little experience in ArcGis but I would like to migrate to
> an open source GIS with an interface with R.
> I know that there are several options: QGIS, SAGA, GRASS, Illwis.
>
> What will be the best option of these or other alternatives?

 What's best for you and best for me depends on what we are trying to do!

 The idea of an 'interface with R' is a bit fluffy, and could be a
number of things. QGis has the wonderful 'manageR' system, which is a
full environment for running and editing R, with rapid exchange of
R-Spatial objects back and forth from QGis. I think Carson is planning
to produce a standalone version that doesn't need QGis as an
independent R GUI, it's *that* good. I only wish I had more time to
help with the dev on that.

 You might also consider PostGIS. This is a spatial database, so you
would keep all your (primarily) vector data in that, and learn the SQL
magic for doing stuff like polygon overlay, point-in-poly,
what's-the-longest-river-that's-partly-in-Worcestershire-that-has-a-newt-density-of-more-than-10-newts/km-when-surveyed-by-either-Dave-or-Nigel-but-not-Simon
questions. You can read PostGIS data into R and use it as the front
end via the sp package mapping functions.

 So many options, so little time! If all you want is pretty map
production then you can do pretty maps in R, or export your final data
as Shapefiles or rasters for import into QGis (or gvSIG, or OpenJump
etc etc) for your open source mapping needs...

Barry