[R-sig-Geo] reading spatial coordinates from a database

Sebastien Sebastien.ollier at u-psud.fr
Fri Aug 31 10:38:39 CEST 2007


Dear R users,

I work with the RODBC package. I would like to read the coordinates xy 
of a polyline in a table called 'populations'. The connexion with the 
database (postgresql) seems good but when I try to select the 
coordinates of a population, the string of characters is truncated at 
255 character which is too short to obtain all the point of the 
corresponding polyline. An example with the populations 5396 :

library(RODBC)
channel <- odbcConnect("colza_ansi")
cde <- paste('select xy from populations where id_pop=5396;')
xy <- sqlQuery(channel, cde)

xy
1 
[(515041.60200000001,2306276.1310000001),(515041.59899999999,2306276.1359999999), 

(515041.59600000002,2306276.1320000002),(515041.59100000001,2306276.1409999998), 

(515041.59100000001,2306276.1340000001),(515041.61700000003,2306276.1170000001), 

(515041.618000


There is probably a parameter to change but I don't find which one. 
Could someone help me?
Thanks

Sébastien Ollier
University of Paris
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