[R-sig-Geo] edit.nb problem with an island

[Wheeler-Martin, Katherine]

Dear all,

I am encountering an issue related to an old thread from 2011 (pasted below), and would like to know if someone could provide sample code for when one wishes to manually delete contiguity between two points, while retaining all other contiguities for those points.

I am relatively new with R, so I apologize if this is obvious!

Thank you,

Katie



Dear Alexander,



Following your suggestion I have used this syntax and works perfectly:



x.nb[[67]] = as.integer(sort(c(43,53)))

x.nb[[43]] = as.integer(sort(c(x.nb[[43]],67)))

x.nb[[53]] = as.integer(sort(c(x.nb[[53]],67)))



Thank you very much for your help!



Marc



2011/5/17 Alexander Werner <werner at wirtschaft.uni-kassel.de<https://stat.ethz.ch/mailman/listinfo/r-sig-geo>>:

> Dear Marc,

>

> facing a similar problem I choose to correct the NB object manually:

>

> NBDKR439[[350]]= as.integer(sort(c(NBDKR439[[350]],362)))

> NBDKR439[[362]]= as.integer(350)

>

> Hope this helps,

> Alexander

>

>

>

> Am 16.05.2011 19:01, schrieb Marc Marí Dell'Olmo:

>>

>> Dear all,

>>

>> I have a cartography with an island, i.e. a polygon that doesn't share

>> border with other polygons (CODIGO=3120104012). I would like to

>> manually assign two areas (CODIGO=3120103024 and CODIGO=3120103014) as

>> a neighborhood areas of this island with the edit.nb function, and

>> after that to obtain the neighborhood matrix. I have followed this

>> syntax and I don't understand why the summary(x.nb2) still shows one

>> region with no link...

>>

>> If it helps, you can download the map at:

>> http://dl.dropbox.com/u/14934021/map.zip

>>

>>

>> Thank you very much,

>>

>> Marc

>>

>> map<-readShapePoly("F:/map/map.shp")

>> map<-map[order(map$CODIGO),]

>>

>>

>> x.nb<-poly2nb(map)

>> summary(x.nb)

>>

>> #Neighbour list object:

>> #Number of regions: 122

>> #Number of nonzero links: 724

>> #Percentage nonzero weights: 4.864284

>> #Average number of links: 5.934426

>> #1 region with no links:

>> #66

>> #Link number distribution:

>>

>>  #0  2  3  4  5  6  7  8  9 10 11 12 14

>>  #1  1  7 19 22 31 21 12  2  2  2  1  1

>> #1 least connected region:

>> #101 with 2 links

>> #1 most connected region:

>> #29 with 14 links

>>

>> nb<- x.nb

>> which(card(nb) == 0)

>> attr(nb, "region.id")[which(card(nb) == 0)]

>>

>>

>> x.nb2<- edit.nb(x.nb,polys=map)

>>

>> #>  x.nb2<- edit.nb(x.nb,polys=map)

>> #Identifying contiguity for deletion ...

>> #No contiguity between chosen points

>> #Add contiguity? (y/n) y

>> #added contiguity between point 53 and 67

>> #Options: quit[q] refresh[r] continue[c] c

>> #Identifying contiguity for deletion ...

>> #No contiguity between chosen points

>> #Add contiguity? (y/n) y

>> #added contiguity between point 43 and 67

>> #Options: quit[q] refresh[r] continue[c] q

>>

>>

>> summary(x.nb2)

>>

>> #Neighbour list object:

>> #Number of regions: 122

>> #Number of nonzero links: 726

>> #Percentage nonzero weights: 4.877721

>> #Average number of links: 5.95082

>> #1 region with no links:

>> #66

>> #Non-symmetric neighbours list

>> #Link number distribution:

>>

>>  #0  2  3  4  5  6  7  8  9 10 11 12 14

>>  #1  1  7 18 22 32 21 12  2  2  2  1  1

>> #1 least connected region:

>> #101 with 2 links

>> #1 most connected region:

>> #29 with 14 links

>>

>> _______________________________________________

>> R-sig-Geo mailing list

>> R-sig-Geo at r-project.org<https://stat.ethz.ch/mailman/listinfo/r-sig-geo>

>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo

>>

>

> --

> Dipl.-Ök. Alexander Werner

> _______________________________________________

> Universität Kassel

> Fachbereich Wirtschaftswissenschaften

> Fachgebiet Empirische Wirtschaftsforschung

> Nora-Platiel-Str. 4

> 34109 Kassel

>

> Tel.: 0561 / 804 - 3044

> werner at wirtschaft.uni-kassel.de<https://stat.ethz.ch/mailman/listinfo/r-sig-geo>

> http://cms.uni-kassel.de/unicms/index.php?id=31247

> _______________________________________________

>

>



Katie Wheeler-Martin, MPH
Senior Data Analyst
Department of Surgery
New York University School of Medicine
550 First Avenue
New York, NY 10016
Office: 1.212.263.6308
katherine.wheeler-martin at nyumc.org<mailto:katherine.wheeler-martin at nyumc.org>


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