[R-sig-Geo] Problems With Cartography 2 - Help

[chris english]

Andres,

I'm thinking you want to 'unsimplify' the topology prior to your poly2nb by
a slight negative gBuffer on the Galapagos polygons,
reduce the Galapagos polygons by the buffer and un-share the boundaries.
I'm trying some code, but looking at a mix of these as
guidance:

https://www.rdocumentation.org/packages/rgeos/versions/0.3-22/topics/gBuffer
https://gist.github.com/mstrimas/1b4a4b93a9d4a158bce4
https://gis.stackexchange.com/questions/93096/how-to-perform-a-true-gis-clip-of-polygons-layer-using-a-polygon-layer-in-r

Saludos,
Chris

On Wed, May 10, 2017 at 4:27 AM, Andrés Peralta <tirico85 at gmail.com> wrote:

> Hi to everyone,
>
> I`m working with the second administrative level cartography from Ecuador
> (available in: http://www.ecuadorencifras.gob.ec//documentos/web-inec/
> Cartografia/2015/Clasificador_Geografico/2012/SHP.zip). The shape file is
> called nxcantones.shp. I`ve been having a lot of problems opening and
> working with this cartography in R; but i can open it in Q-GIS and ARCGIS
> without any problem (I have opened it in both programs and saved it again).
> As the cartography has various objects with the same ID - aparently the
> same areas but repeated; we had to run the following sintax in order to
> have one ID in each area:
>
> *carto2012 <- readOGR("CANTONES2012/2012CLEAN.shp", "2012CLEAN",
> stringsAsFactors=F) *
> *proj4string(carto2012) <- CRS("+proj=utm +zone=17 +south +datum=WGS84
> +units=m +no_defs")*
>
> *carto2012x <- unionSpatialPolygons(carto2012, IDs=carto2012$DPA_CANTON)*
> *proj4string(carto2012x) <- CRS("+proj=utm +zone=17 +south +datum=WGS84
> +units=m +no_defs")*
>
>
> *datos <- data.frame(ID=row.names(carto2012x), stringsAsFactors = F)*
> *row.names(datos) <- row.names(carto2012x)*
> *carto2012x2 <- SpatialPolygonsDataFrame(carto2012x, data=datos)*
>
> *carto2012 <- carto2012x2 *
>
> For our work, we had to make a neighborhood matrix of the cartography.
>
> *x.nb <- poly2nb(carto2012u2) # U2 is the cartography after the recode of
> some areas that had to be joined.*
>
> *summary(x.nb)*
>
> This seems to work fine. The problem is we need to connect the three island
> areas (the Galapagos) but when we try to do so, it connects many areas
> along all the cartography. I've tried to do it manually using *edit.nb* but
> it does not work. I´ve also tried the following sintaxes:
>
> x.nb1 <- x.nb
> which(card(x.nb1)==0) #to discover the id of these areas without
> connections
> id <- function(x){which(carto2012u2$ID==x)}
>
> x.nb1[[id(2001)]] = unique(as.integer(sort(c(x.nb1[[id(2001)]],
> id(2002)))))
> x.nb1[[id(2002)]] = unique(as.integer(sort(c(x.nb1[[id(2002)]],
> id(2001)))))
>
> x.nb1[[id(2001)]] = unique(as.integer(sort(c(x.nb1[[id(2001)]],
> id(2003)))))
> x.nb1[[id(2003)]] = unique(as.integer(sort(c(x.nb1[[id(2003)]],
> id(2001)))))
>
> x.nb1[[id(2002)]] = unique(as.integer(sort(c(x.nb1[[id(2002)]],
> id(2003)))))
> x.nb1[[id(2003)]] = unique(as.integer(sort(c(x.nb1[[id(2003)]],
> id(2002)))))
>
> ####
> x.nb1[[id("2001")]] = unique(as.integer(sort(c(x.nb1[[id("2001")]],
> id("2002")))))
> x.nb1[[id("2002")]] = unique(as.integer(sort( id("2001"))))
>
> x.nb1[[id("2001")]] = unique(as.integer(sort(c(x.nb1[[id("2001")]],
> id("2003")))))
> x.nb1[[id("2003")]] = unique(as.integer(sort( id("2001"))))
>
> x.nb1[[id("2002")]] = unique(as.integer(sort(c(x.nb1[[id("2002")]],
> id("2003")))))
> x.nb1[[id("2003")]] = unique(as.integer(sort( id("2002"))))
>
> Any ideas or suggestions? Your help will really be appreciated.
>
>
> --
>
> *             Andrés Peralta*
>         Pre-doctoral Researcher
>      GREDS/EMCONET / ASPB
> <https://www.upf.edu/greds-emconet/en/>   <http://aspb.cat/>
>
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>
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