Thanks a lot for the hints. I will try. Actually I was focusing (in a first stage) on simple segments (small mammal traplines...). I turned the problem out writing some lines to export the coordinates into a "simple" GRASS ascii file, imported it into GRASS as vector file and then used the export tool to get shapefiles... Not that direct: needs to have GRASS installed and an elementary knowledge on the export/import commands in this open source GIS.
It would be fantastic to have the reverse functions of Map2poly(Map), Map2lines(Map), Map2points(Map) read.shape (eg poly2map, lines2map, points2map, and write.map) to write shapefiles.... I must however admit that I don't know enough about shapefile formats and R programming to do this by myself... and I would unfortunately be really out of my current job in the university... ----- Original Message ----- From: "Stephane DRAY" <[EMAIL PROTECTED]> To: "Patrick Giraudoux" <[EMAIL PROTECTED]>; "r-help" <[EMAIL PROTECTED]> Sent: Wednesday, February 25, 2004 5:35 PM Subject: Re: [R] writing polygons/segments to shapefiles (.shp) or other ArCGIS compatible file > There is a little problem with the approach I described in my previous email. > In ADE-4, coordinates are given in pixel and so Y are inverted. You must > invert your Y coordinates to obtain the good representation in ArcView. An > example: > > > library(ade4) > > library(shapefiles) > > library(maptools) > > try1 <- read.shapefile(paste(ShapeDir, "columbus", sep="/")) > > shppolys <- shape2poly(try1, as.character(try1$dbf$dbf$NEIGNO)) > > obj=poly2area(shppolys) > > obj[,3]=-obj[,3] > > write.table(obj,"try.area",col.names=F,quote=F,row.names=F) > > > > Then, use the 'From AREA' function in AVADE. > > > > At 10:32 25/02/2004, Patrick Giraudoux wrote: > >I am not sure a previous e-mail reached the list (no mail aknowledgement > >from R-boundle etc.). The question was how to write polygon > >or segment coordinates into a shapefile set or any other ArcGIS supported > >format. The library shapefiles seems to do something but > >the documentation is a bit beyond of my mind.... and I cannot get the > >meaning of the functions write**** and its application to the > >case below: > > > >In simple words, is there a somewhere a function taking polygon > >coordinates (or simple segments) within R to a "ready to read" set > >of files ***.shp, ***.shx, etc... > > > >Thanks in advance for any hint > > > >Patrick > > > > > > > >----- Original Message ----- > >From: "Patrick Giraudoux" <[EMAIL PROTECTED]> > >To: "r-help" <[EMAIL PROTECTED]> > >Sent: Wednesday, February 25, 2004 1:08 PM > >Subject: writing polygons/segments to shapefiles (.shp) > > > > > > > Dear all, > > > > > > The library maptools offers a fantastic support for shapefile reading. > > > > > > Is there a R library available permitting the writing of polygon or > > segment coordinates into shapefile? > > > > > > Thanks for any hint, > > > > > > Patrick Giraudoux > > > > > > > > > > > > > > > >______________________________________________ > >[EMAIL PROTECTED] mailing list > >https://www.stat.math.ethz.ch/mailman/listinfo/r-help > >PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > > Stéphane DRAY > -------------------------------------------------------------------------------------------------- > > > Département des Sciences Biologiques > Université de Montréal, C.P. 6128, succursale centre-ville > Montréal, Québec H3C 3J7, Canada > > Tel : 514 343 6111 poste 1233 > E-mail : [EMAIL PROTECTED] > -------------------------------------------------------------------------------------------------- > > > Web http://www.steph280.freesurf.fr/ > -------------------------------------------------------------------------------------------------- > > > ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html