tom sgouros <tomf...@as220.org> wrote: > > Dan Putler <dan.put...@sauder.ubc.ca> wrote:
> > 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. I should have also said that I have both SHP files and E00 files to describe the boundaries of the districts, but have no feeling about which I should prefer or why and I wonder if anyone else does. The SHP files come with an XML description that seems not to be used by grass. The E00 files maybe come with a description of their own projection, while I had to identify a projection to specify it to grass, but otherwise I don't know why one would be better or worse. Thanks, -tom > > 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 > > > > > On Sun, 2009-11-15 at 22:30 -0500, tom sgouros wrote: > > > Raphael Saldanha <saldanha.plan...@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.plan...@gmail.com > > > > > > > > [[alternative HTML version deleted]] > > > > > > > > _______________________________________________ > > > > R-sig-Geo mailing list > > > > R-sig-Geo@stat.math.ethz.ch > > > > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > > > > > > > > > > > > -- > > Dan Putler > > Sauder School of Business > > University of British Columbia > > > > > -- > -------------------------------------------------------- > Check out "Ten Things You Don't Know About Rhode Island" > http://whatcheer.net http://sgouros.com > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > -- -------------------------------------------------------- Check out "Ten Things You Don't Know About Rhode Island" http://whatcheer.net http://sgouros.com _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo