[R-sig-Geo] PostGIS and sp integration

Edzer Pebesma edzer.pebesma at uni-muenster.de
Thu Oct 9 17:04:07 CEST 2008

Barry Rowlingson wrote:
> 2008/10/9 Edzer Pebesma <edzer.pebesma at uni-muenster.de>:
>> Why is this better practice than having a single 100x61 table with monthly
>> rainfall in the usual columns and a geometry column?
>  Because when I get another year's data, I have to change the table
> definition. SQL doesn't like that[1]. Keep your original data
> normalised, that's the idea. Of course you can denormalise for a
> specific purpose, such as....
Right, I forgot, SQL doesn't have the $<-
>> Sounds as if you've not seen the spplot light. If you had a single table
>> with 60 columns and 100 rows, all that's needed would be
>> rain = readOGR("bla")
>> spplot(rain)
>> given that the rain columns would be useful and fit in the conditioning plot
>> text boxes (so-called "strips")
>  I'll give that a go. However, I need to get my 60 plots into 60 png
> files for animation purposes. Can spplot do that? I was just going to
> draw them into png() devices.
Yes, but you need to fix the scale bar range ahead of time. spplot is 
just a wrapper around levelplot, so remember to put a print(spplot(...)) 
inside loops.
>  Originally I had weekly data...
Well, yes, in that case animation becomes compelling. Aren't there any 
GIS clients that can do animation with time series of vector maps? I 
only know one for gridded data.

Edzer Pebesma
Institute for Geoinformatics (ifgi), University of Münster,
Weseler Straße 253, 48151 Münster, Germany.  Phone: +49 251
8333081, Fax: +49 251 8339763  http://ifgi.uni-muenster.de/

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