[R-sig-Geo] newbie questions

[tom sgouros]

Raphael Saldanha <saldanha.plangeo at gmail.com> wrote:

> Hi Tom!
> 
> I'm a geographer and R enthusiast too, but what I can say is: R is a great
> software to statistics. The final production of maps, although it's
> possible, it's simple and faster made with GIS softwares, like GRASS,
> Quantum GIS or ArcGIS.

This is exactly my quandary.  I have some data I want to map, and I have
no idea how to do it and none of the introductions I've found speak to
what I thought was a pretty simple task.

I first thought maybe I should use a GIS, since it's geographic data,
but all the GIS documentation I can find is about how to analyze data
that's already available.  There are no end of Grass examples using this
North Carolina dataset that comes with the installation, but I don't
live in North Carolina and I don't want to analyze their data.  I want
to analyze mine, but I can't figure out how to get it in, and that's
what I'm using R for.

If you are telling me there is a simpler way to do this, I am all ears
(eyes), especially if it uses grass or qgis which I can afford, and not
Arc, which I can't.

Queries of GIS guys told me that what I need to do is to get my data
into a shape file first and then a GIS can help me display it, so I
turned to R for that.  Was I wrong there, too?

Most of the data I want to map is not currently in any format at all.
It's just numbers I have.  I have shape files for the geography and I
want to apply my numbers to those shapes and draw maps in color, and I
also would very much like to draw the 3d kind where the geographic area
is raised up according to some value.  (I don't know if there's a name
for this.)  I tried to use a spreadsheet to get my data attached to the
shapes, but as soon as I realized I needed to do a join of my data and
the shape file data I began to look for alternatives.

I know that I'm working at a very low level here, but in addition to
Roger's advice before about how to get R to cooperate, I would be
grateful for any advice such as you've provided about what exactly R is
good for in my task and what a GIS is good for.  Your note advances me
down the field quite a bit, but if there's more, I'd be interested to
know it.

Many thanks,

 -tom



> 
> My tip is: organize data with spreadsheet and GIS softwares, import (as
> shapefile, if possible) in R and make your statistical analysis and
> statistical columns of data, export to another shapefile and manipulate the
> final map in GIS softwares.
> 
> I repeat, it's possible make all these steps in R, and generate great maps,
> but the most simple way is above. Personally, I use R to make the final maps
> only when I have to produce a long series of simple maps.
> 
> I think the best way is the integration of GIS software with R, each one
> with his specialty.
> 
> 
> King regards,
> 
> Raphael Saldanha
> BRAZIL
> saldanha.plangeo at gmail.com
> 
> 	[[alternative HTML version deleted]]
> 
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