On Fri, 5 Nov 2010, Rodrigo Aluizio wrote:
Hi List.
I?m trying to solve an issue here, but it?s getting tricky.
I have an MapGen .dat file (attached) that contains about 39 closed lines.
Three of them (the largest ones) will be my main polygons and the rest of
them must become holes inside one of the three major areas. I?m able to
transform all the closed lines into SpatialPolygons and even create
shapefiles with them, but how can I modify the ?hole? slot of the smaller
polygons so I can keep them transparent when overlaying another map (those
holes will overlay islands of a raster image)?
Next time avoid sending 200K to over 1700 people, please, we have a planet
to protect! Put any desired attachments on a website and provide a link.
You should also have provided the code (in your message) to get from:
library(maptools)
l1 <- MapGen2SL("PCForams.dat")
to your problem - as those choices may be the cause of the problem; you
have not provided the output of sessionInfo() either. Once things are
lined up, you should - if you may - say:
gpclibPermit() # very restrictive license
pls_out <- lapply(slot(SpPols0, "polygons"), checkPolygonsHoles)
SpPols1 <- SpatialPolygons(pls_out)
Or if you can install rgeos from source on R-Forge, equivalently:
library(rgeos)
SpPols1 <- createSPComment(SpPols0)
Hope this helps,
Roger
Thank you for the attention and help.
Regards.
-------------------------------------------------------------------
MSc. <mailto:r.alui...@gmail.com> Rodrigo Aluizio
Centro de Estudos do Mar/UFPR
Laboratório de Foraminíferos e Micropaleontologia Ambiental
Avenida Beira Mar s/n - CEP 83255-971
Pontal do Paraná - PR - Brazil
--
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: roger.biv...@nhh.no
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