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Convert grids with 0/1 attribute to polygons with neighbor grids of same values merged
2 messages · zhijie zhang, Roger Bivand
On Thu, 28 Jan 2010, zhijie zhang wrote:
Sorry. It seems that the above idea is not easy to get through. I tried it for some time. Hope Someone else can solve it.
Almost there - you needed: spol1 <- unionSpatialPolygons(as(spol, "SpatialPolygons"), as.character(spol$xvs)) image(grd, axes=TRUE) plot(spol1, add=TRUE) to complete, then I guess promotion back to a SpatialPolygonsDataFrame, then writing out for each type separately to shapefile. Roger
On Wed, Jan 27, 2010 at 10:13 PM, zhijie zhang <epistat at gmail.com> wrote:
Hi, I cannot successfully do it, but may provide my idea on this. Somebody else may solve it. ###Example Data### library(maptools) gt <- GridTopology(c(0.05,0.05), c(0.1,0.1), c(10,10)) xv<-rnorm(length(coordinates(gt)[,1])) xvs<-ifelse(xv>0.2,1,0) grd <- SpatialGridDataFrame(gt, data.frame(xvs),proj4string=CRS(as.character(NA))) #grdM<-as.matrix(data.frame(coordinates(grd),grd at data)) #grdM[1:5,] spplot(grd) ####Transform into polygons#### spix <- as(grd, "SpatialPixelsDataFrame") spol <- as(spix, "SpatialPolygonsDataFrame") ####Create two subset polygons based on 0 or 1###### spol1<-spol[spol$xvs==1,] plot(spol1) #Four polygons spol0<-spol[spol$xvs==0,] plot(spol0) #one separate grid and a large irregualr polygon #From their plots,we can see they can merge into four polygons for "spol1" and two polygons for "spol0". ###If we plot their neighbors, it will be more clear to see how many polygons there should be after merging ###### library(spdep) nbs<-poly2nb(spol1, queen=TRUE) plot(spol1) #Four polygons plot.nb(nbs, coordinates(spol1),add=TRUE) nbs2<-poly2nb(spol0, queen=TRUE) plot(spol0) #Two polygons plot.nb(nbs2, coordinates(spol0),add=TRUE) ############### I wonder whether it is feasible for the following idea based on the queen neighbors. Step1:We can first select one grid, and merge it with its queen neighbors. Then generate a new polygon for this merged grids. Step2: Continue to merge the newly generated polygon with its queen neighbors. Then generate a newer polygon for these merged grids. Repeat step1 and step2 until all the related grids were merged. This is one separate large polygon. Step3: Then select another isolated grid, and repeat the step1 and step2 to generate another polygon. Continue....Until all the separated polygons were merged.That is the queen neighbors will be zero finally. Is this possible? Hope someone can solve this. Some other ideas maybe better. On Wed, Jan 27, 2010 at 6:00 AM, <r-sig-geo-request at stat.math.ethz.ch>wrote:
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https://stat.ethz.ch/mailman/listinfo/r-sig-geo or, via email, send a message with subject or body 'help' to r-sig-geo-request at stat.math.ethz.ch You can reach the person managing the list at r-sig-geo-owner at stat.math.ethz.ch When replying, please edit your Subject line so it is more specific than "Re: Contents of R-sig-Geo digest..." Today's Topics: 1. Re: rgdal 64bit Windows version? (Rainer Hurling) 2. Re: points to lines and/or polygons (Roger Bivand) 3. Distance to (nearest) polygon (Karl Ove Hufthammer) 4. Re: Distance to (nearest) polygon (Roger Bivand) 5. maxdist for kriging with an external drift (Els Verfaillie) 6. Re: maxdist for kriging with an external drift (Edzer Pebesma) 7. Re: maxdist for kriging with an external drift (Cutberto Uriel Paredes Hern?ndez) 8. Edit a Sptial Lines Object (Rodrigo Aluizio) 9. Re: maxdist for kriging with an external drift (Edzer Pebesma) 10. Re: maxdist for kriging with an external drift (Paulo Justiniano Ribeiro Jr) 11. Convert grids with 0/1 attribute to polygons with neighbor grids of same values merged (rusers.sh) 12. Re: complement part of a polygon in another polygon (rusers.sh) 13. kriging as fish swim, not as crows fly (Martin Renner) 14. Re: Distance to (nearest) polygon (Karl Ove Hufthammer) 15. Re: kriging as fish swim, not as crows fly (Michael Sumner) ---------------------------------------------------------------------- Message: 1 Date: Tue, 26 Jan 2010 12:01:45 +0100 From: Rainer Hurling <rhurlin at gwdg.de> To: Michael Sumner <mdsumner at gmail.com> Cc: r-sig-geo at stat.math.ethz.ch Subject: Re: [R-sig-Geo] rgdal 64bit Windows version? Message-ID: <4B5ECB99.4040602 at gwdg.de> Content-Type: text/plain; charset=UTF-8; format=flowed Am 25.01.2010 22:25 (UTC+1) schrieb Michael Sumner: I suspect you'll need to build GDAL for yourself and then build rgdal on top of that, since rgdal depends upon a pre-installation of GDAL. The gdal-dev list is the appropriate place for discussing the first step. Colleagues have succesfully built 64-bit Windows GDAL from the 1.6.0 release using extra binaries (HDF4/5, NetCDF, etc.) from here: http://vbkto.dyndns.org:1280/sdk/Default.aspx Thanks, Michael, for this interesting link. Unfortunately we are not able to build our own versions on windows machines because of administrative reasons. I will have a look at it in my spare time ;-) Rainer There are notes on build rgdal for Windows here, but I've not done it myself for a while: file.show(system.file("README.windows", package="rgdal")) I am keen to try this for myself, but it will not be for a while yet. Best regards, Mike On Tue, Jan 26, 2010 at 8:04 AM, Rainer Hurling<rhurlin at gwdg.de> wrote: Some days ago Brian Ripley and Uwe Ligges announced an update to MinGW-w64 builds for 64-bit Windows on R-devel at . This daily version works really nice. But it is not fully applicable at this time because of some missing packages. I am in particular interested in a 64-bit version of rgdal, which depends on a 64-bit version of gdal(.dll). Is their anything known about what is planned with this important part of spatial software? ------------------------------ Message: 2 Date: Tue, 26 Jan 2010 13:54:27 +0100 (CET) From: Roger Bivand <Roger.Bivand at nhh.no> To: Agustin Lobo <alobolistas at gmail.com> Cc: r-sig-geo at stat.math.ethz.ch Subject: Re: [R-sig-Geo] points to lines and/or polygons Message-ID: <alpine.LRH.2.00.1001261350580.14929 at reclus.nhh.no> Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed On Tue, 26 Jan 2010, Agustin Lobo wrote: Hi! Package StatDA provides background geoinformation as a set of coordinates: str(kola.background) List of 4 $ boundary:'data.frame': 50 obs. of 2 variables: ..$ V1: num [1:50] 388650 388160 386587 384035 383029 ... ..$ V2: num [1:50] 7892400 7881248 7847303 7790797 7769214 ... $ coast :'data.frame': 6259 obs. of 2 variables: ..$ V1: num [1:6259] 438431 439102 439102 439643 439643 ... ..$ V2: num [1:6259] 7895619 7896495 7896495 7895800 7895542 ... $ borders :'data.frame': 504 obs. of 2 variables: ..$ V1: num [1:504] 417575 417704 418890 420308 422731 ... ..$ V2: num [1:504] 7612984 7612984 7613293 7614530 7615972 ... $ lakes :'data.frame': 6003 obs. of 2 variables: ..$ V1: num [1:6003] 547972 546915 NA 547972 547172 ... ..$ V2: num [1:6003] 7815109 7815599 NA 7815109 7813873 ... is there any spatial function aready availale to convert these coordinates into Spatial Lines and Spatial Polygons? This seems to work at least for SpatialLines - for polygons, the rings may need to be closed: library(StatDA) data(kola.background) xy <- kola.background$boundary names(xy) <- c("x", "y") library(maptools) bdy <- map2SpatialLines(xy) plot(bdy) The data are in the legacy S format (like the maps package). Roger Thanks Agus [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo at stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo -- 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.Bivand at nhh.no ------------------------------ Message: 3 Date: Tue, 26 Jan 2010 16:02:27 +0100 From: Karl Ove Hufthammer <karl at huftis.org> To: r-sig-geo at stat.math.ethz.ch Subject: [R-sig-Geo] Distance to (nearest) polygon Message-ID: <MPG.25c9226ee5625bb49896d3 at news.gmane.org> Content-Type: text/plain; charset="us-ascii" Dear list members Is there an easy and preferably fast way to measure the distance from a of (large) number of points to the nearest polygon? spDistsN1 seems to only want to measure the distance between points. For example, I need the distance between points at sea to the nearest land area (as defined by for example the 'world' dataset). It's not very important which polygon, e.g., country, the given distance is to. It would be nice if the 'distance' from points that are inside the polygons were zero or negative, but it's not required -- distance to the polygon border, e.g., shoreline, would be OK. -- Karl Ove Hufthammer ------------------------------ Message: 4 Date: Tue, 26 Jan 2010 16:27:23 +0100 (CET) From: Roger Bivand <Roger.Bivand at nhh.no> To: Karl Ove Hufthammer <karl at huftis.org> Cc: r-sig-geo at stat.math.ethz.ch Subject: Re: [R-sig-Geo] Distance to (nearest) polygon Message-ID: <alpine.LRH.2.00.1001261625260.17754 at reclus.nhh.no> Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed On Tue, 26 Jan 2010, Karl Ove Hufthammer wrote: Dear list members Is there an easy and preferably fast way to measure the distance from a of (large) number of points to the nearest polygon? spDistsN1 seems to only want to measure the distance between points. For example, I need the distance between points at sea to the nearest land area (as defined by for example the 'world' dataset). It's not very important which polygon, e.g., country, the given distance is to. It would be nice if the 'distance' from points that are inside the polygons were zero or negative, but it's not required -- distance to the polygon border, e.g., shoreline, would be OK. There are methods for point to line segment distances in spatstat. Further, for projected (planar) coordinates, this could be added to R-Forge rgeos; for geographical coordinates Boost ggl would be needed. Roger -- 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.Bivand at nhh.no ------------------------------ Message: 5 Date: Tue, 26 Jan 2010 17:00:29 +0100 From: "Els Verfaillie" <els.verfaillie at ugent.be> To: <r-sig-geo at stat.math.ethz.ch> Subject: [R-sig-Geo] maxdist for kriging with an external drift Message-ID: <005d01ca9ea0$aed17900$0c746b00$@verfaillie at ugent.be> Content-Type: text/plain Dear list, I want to use Kriging with an external drift for a sedimentological dataset of grain-size that has a linear relation with the depth. Am I correct that when I set a 'maxdist' using the krige command, that a trend for the primary variable (grain-size) is calculated as a local linear function of the secondary variable (depth)? Is this function thus different for each interpolation window? d50.ked.dir50 <- krige(D50F~depth, locations=ds50, newdata=Depth, model=d50.fit.var.50, nmin=2, nmax=16, maxdist=9000) Thank you for your help. Best regards, Els Verfaillie ______________________________________________ Dr. Els Verfaillie Carto-GIS cluster Ghent University (UGent) - Department of Geography ______________________________________________ [[alternative HTML version deleted]] ------------------------------ Message: 6 Date: Tue, 26 Jan 2010 17:05:03 +0100 From: Edzer Pebesma <edzer.pebesma at uni-muenster.de> To: Els Verfaillie <els.verfaillie at ugent.be> Cc: r-sig-geo at stat.math.ethz.ch Subject: Re: [R-sig-Geo] maxdist for kriging with an external drift Message-ID: <4B5F12AF.5070302 at uni-muenster.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Yes, that is right. Els Verfaillie wrote: Dear list, I want to use Kriging with an external drift for a sedimentological dataset of grain-size that has a linear relation with the depth. Am I correct that when I set a 'maxdist' using the krige command, that a trend for the primary variable (grain-size) is calculated as a local linear function of the secondary variable (depth)? Is this function thus different for each interpolation window? d50.ked.dir50 <- krige(D50F~depth, locations=ds50, newdata=Depth, model=d50.fit.var.50, nmin=2, nmax=16, maxdist=9000) Thank you for your help. Best regards, Els Verfaillie ______________________________________________ Dr. Els Verfaillie Carto-GIS cluster Ghent University (UGent) - Department of Geography ______________________________________________ [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo at stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo -- Edzer Pebesma Institute for Geoinformatics (ifgi), University of M?nster Weseler Stra?e 253, 48151 M?nster, Germany. Phone: +49 251 8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de http://www.52north.org/geostatistics e.pebesma at wwu.de ------------------------------ Message: 7 Date: Tue, 26 Jan 2010 16:45:00 +0000 From: Cutberto Uriel Paredes Hern?ndez <cutberto.paredes at gmail.com> To: Edzer Pebesma <edzer.pebesma at uni-muenster.de>, r-sig-geo at stat.math.ethz.ch Subject: Re: [R-sig-Geo] maxdist for kriging with an external drift Message-ID: <8f1fabf91001260845n632ad13ek418a695e27110de8 at mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Dear Edzer, Would it be correct to say then that if a neighbourhood is specified in the krige command the result would be that of Kriging with an External Drift (KED), otherwise it would be that of Simple Kriging with varying local means (SKlm)? Apologies for posting on this thread but I was about to post a similiar question. Thanks, Cutberto. 2010/1/26 Edzer Pebesma <edzer.pebesma at uni-muenster.de>: Yes, that is right. Els Verfaillie wrote: Dear list, I want to use Kriging with an external drift for a sedimentological dataset of grain-size that has a linear relation with the depth. Am I correct that when I set a 'maxdist' using the krige command, that a trend for the primary variable (grain-size) is calculated as a local linear function of the secondary variable (depth)? Is this function thus different for each interpolation window? d50.ked.dir50 <- krige(D50F~depth, locations=ds50, newdata=Depth, model=d50.fit.var.50, nmin=2, nmax=16, maxdist=9000) Thank you for your help. Best regards, Els Verfaillie ______________________________________________ Dr. Els Verfaillie Carto-GIS cluster Ghent University (UGent) - Department of Geography ______________________________________________ ? ? ? ?[[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo at stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo -- Edzer Pebesma Institute for Geoinformatics (ifgi), University of M?nster Weseler Stra?e 253, 48151 M?nster, Germany. Phone: +49 251 8333081, Fax: +49 251 8339763 ?http://ifgi.uni-muenster.de http://www.52north.org/geostatistics ?e.pebesma at wwu.de _______________________________________________ R-sig-Geo mailing list R-sig-Geo at stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo ------------------------------ Message: 8 Date: Tue, 26 Jan 2010 15:02:40 -0200 From: "Rodrigo Aluizio" <r.aluizio at gmail.com> To: "R Help" <r-sig-geo at stat.math.ethz.ch> Subject: [R-sig-Geo] Edit a Sptial Lines Object Message-ID: <4b5f2052.9c15f10a.7b9d.0861 at mx.google.com> Content-Type: text/plain; charset="iso-8859-1" Hi list, I?m trying to insert some coordinates at the end of an object (attached) component (BP[1]). But I?m not able to do so. I can?t isolate the coordinates, if I use the ?@lines? it turns into a list, but I need to keep the SpatialLines and S4 structure, then I will be able to transform the closed lines into polygons. So, How can I insert the coordinates that will close the BP[1] line into this object without changing the object properties. Any Ideas? Thank you in advance. ------------------------------------------------------------- MSc. <mailto:r.aluizio at gmail.com> Rodrigo Aluizio Centro de Estudos do Mar/UFPR Laborat?rio de Micropaleontologia Avenida Beira Mar s/n - CEP 83255-000 Pontal do Paran? - PR - Brasil Fone: (41) 3511-8657 Fax: (41) 3455-3623 -------------- next part -------------- An HTML attachment was scrubbed... URL: < https://stat.ethz.ch/pipermail/r-sig-geo/attachments/20100126/63ec934e/attachment-0001.html -------------- next part -------------- A non-text attachment was scrubbed... Name: BP.Rdata Type: application/octet-stream Size: 39731 bytes Desc: not available URL: < https://stat.ethz.ch/pipermail/r-sig-geo/attachments/20100126/63ec934e/attachment-0001.obj ------------------------------ Message: 9 Date: Tue, 26 Jan 2010 21:11:47 +0100 From: Edzer Pebesma <edzer.pebesma at uni-muenster.de> To: Cutberto Uriel Paredes Hern?ndez <cutberto.paredes at gmail.com> Cc: r-sig-geo at stat.math.ethz.ch Subject: Re: [R-sig-Geo] maxdist for kriging with an external drift Message-ID: <4B5F4C83.7040808 at uni-muenster.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Oh, geostatistics and its funny naming conventions! I see local models vs. global models as a completely different modelling aspect (model decision, basically) then the SK/OK/UK differences. When building on the same tradition / body of literature you quote: in that case KED would be a special form of UK, having only a single non-coordinate predictor called 'external drift'. In my eyes (and that of the literature with more mathematical statistical grounding, such as Cressie 1993 and others), the difference between SK on the one hand and OK/UK on the other is that SK assumes that you know the mean or mean structure. SKlm is then residual kriging added to a known mean function. In the gstat R package you obtain SK by specifying a beta value (for the mean); SKlm by specifying one or more predictors and passing the (known) regression coefficients as beta; you obtain OK/UK by not specifying beta; a formula ending on ~1 results in OK with an unknown mean only. Ah, and then SK = simple kriging, OK = ordinary kriging, UK = universal kriging. -- Edzer Cutberto Uriel Paredes Hern?ndez wrote: Dear Edzer, Would it be correct to say then that if a neighbourhood is specified in the krige command the result would be that of Kriging with an External Drift (KED), otherwise it would be that of Simple Kriging with varying local means (SKlm)? Apologies for posting on this thread but I was about to post a similiar question. Thanks, Cutberto. 2010/1/26 Edzer Pebesma <edzer.pebesma at uni-muenster.de>: Yes, that is right. Els Verfaillie wrote: Dear list, I want to use Kriging with an external drift for a sedimentological dataset of grain-size that has a linear relation with the depth. Am I correct that when I set a 'maxdist' using the krige command, that a trend for the primary variable (grain-size) is calculated as a local linear function of the secondary variable (depth)? Is this function thus different for each interpolation window? d50.ked.dir50 <- krige(D50F~depth, locations=ds50, newdata=Depth, model=d50.fit.var.50, nmin=2, nmax=16, maxdist=9000) Thank you for your help. Best regards, Els Verfaillie ______________________________________________ Dr. Els Verfaillie Carto-GIS cluster Ghent University (UGent) - Department of Geography ______________________________________________ [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo at stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo -- Edzer Pebesma Institute for Geoinformatics (ifgi), University of M?nster Weseler Stra?e 253, 48151 M?nster, Germany. Phone: +49 251 8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de http://www.52north.org/geostatistics e.pebesma at wwu.de _______________________________________________ R-sig-Geo mailing list R-sig-Geo at stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo -- Edzer Pebesma Institute for Geoinformatics (ifgi), University of M?nster Weseler Stra?e 253, 48151 M?nster, Germany. Phone: +49 251 8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de http://www.52north.org/geostatistics e.pebesma at wwu.de ------------------------------ Message: 10 Date: Tue, 26 Jan 2010 18:31:00 -0200 (BRST) From: Paulo Justiniano Ribeiro Jr <paulojus at c3sl.ufpr.br> To: Edzer Pebesma <edzer.pebesma at uni-muenster.de> Cc: r-sig-geo at stat.math.ethz.ch Subject: Re: [R-sig-Geo] maxdist for kriging with an external drift Message-ID: <alpine.DEB.1.10.1001261822570.28905 at dalmore.c3sl.ufpr.br> Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" May be worth adding here that, despite algorithms and the "funny naming conventions" (good descrition Edzer!) SK and others are diferent in the following way: SK, as described in Edzer post, assumes you **know** the mean, in other words, there is no uncertainty about it. On the other hand, variants such as OK, UK, KED, SKlm uses (explicitly or implicitly) estimated means. Therefore, such uncertainty has to be propagated and reflected in the predictions. Suposse the fixed mean in SK is the same as the (implicitly) estimated by OK. The point predictions will be the same, however, the uncertainty around them will not (and should not) refleting the uncertainty (or lack of it) in the process mean. The prediction variance expressions for SK ond OK will reflect this whatever the kriging neighborhood is used. best P.J. On Tue, 26 Jan 2010, Edzer Pebesma wrote: Oh, geostatistics and its funny naming conventions! I see local models vs. global models as a completely different modelling aspect (model decision, basically) then the SK/OK/UK differences. When building on the same tradition / body of literature you quote: in that case KED would be a special form of UK, having only a single non-coordinate predictor called 'external drift'. In my eyes (and that of the literature with more mathematical statistical grounding, such as Cressie 1993 and others), the difference between SK on the one hand and OK/UK on the other is that SK assumes that you know the mean or mean structure. SKlm is then residual kriging added to a known mean function. In the gstat R package you obtain SK by specifying a beta value (for the mean); SKlm by specifying one or more predictors and passing the (known) regression coefficients as beta; you obtain OK/UK by not specifying beta; a formula ending on ~1 results in OK with an unknown mean only. Ah, and then SK = simple kriging, OK = ordinary kriging, UK = universal kriging. -- Edzer Cutberto Uriel Paredes Hern?ndez wrote: Dear Edzer, Would it be correct to say then that if a neighbourhood is specified in the krige command the result would be that of Kriging with an External Drift (KED), otherwise it would be that of Simple Kriging with varying local means (SKlm)? Apologies for posting on this thread but I was about to post a similiar question. Thanks, Cutberto. 2010/1/26 Edzer Pebesma <edzer.pebesma at uni-muenster.de>: Yes, that is right. Els Verfaillie wrote: Dear list, I want to use Kriging with an external drift for a sedimentological dataset of grain-size that has a linear relation with the depth. Am I correct that when I set a 'maxdist' using the krige command, that a trend for the primary variable (grain-size) is calculated as a local linear function of the secondary variable (depth)? Is this function thus different for each interpolation window? d50.ked.dir50 <- krige(D50F~depth, locations=ds50, newdata=Depth, model=d50.fit.var.50, nmin=2, nmax=16, maxdist=9000) Thank you for your help. Best regards, Els Verfaillie ______________________________________________ Dr. Els Verfaillie Carto-GIS cluster Ghent University (UGent) - Department of Geography ______________________________________________ [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo at stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo -- Edzer Pebesma Institute for Geoinformatics (ifgi), University of M?nster Weseler Stra?e 253, 48151 M?nster, Germany. Phone: +49 251 8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de http://www.52north.org/geostatistics e.pebesma at wwu.de _______________________________________________ R-sig-Geo mailing list R-sig-Geo at stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo -- Edzer Pebesma Institute for Geoinformatics (ifgi), University of M?nster Weseler Stra?e 253, 48151 M?nster, Germany. Phone: +49 251 8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de http://www.52north.org/geostatistics e.pebesma at wwu.de _______________________________________________ R-sig-Geo mailing list R-sig-Geo at stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo Paulo Justiniano Ribeiro Jr LEG (Laboratorio de Estatistica e Geoinformacao) Universidade Federal do Parana Caixa Postal 19.081 CEP 81.531-990 Curitiba, PR - Brasil Tel: (+55) 41 3361 3573 Fax: (+55) 41 3361 3141 e-mail: paulojus AT ufpr br http://www.leg.ufpr.br/~paulojus ------------------------------ Message: 11 Date: Tue, 26 Jan 2010 22:53:15 -0500 From: "rusers.sh" <rusers.sh at gmail.com> To: r-sig-geo at stat.math.ethz.ch Subject: [R-sig-Geo] Convert grids with 0/1 attribute to polygons with neighbor grids of same values merged Message-ID: <a835c81e1001261953w69656b0cg3400793f92a4a412 at mail.gmail.com> Content-Type: text/plain Dear all, Somebody has discussed the similar question before, "converting grid objects to spatial polygon objects and export as shapefile ( https://stat.ethz.ch/pipermail/r-sig-geo/2009-December/007163.html)", where they have successfully convert the grids into spatial polygons. But the generated polygons didnot merge any original grids. Now, i have a grid dataset, its attribute is 0/1 variable. So finally i hope to get two shape files, one is its attribute being 0, another is attribute being 1. But particularly, i hope to merge the grids if their attribute's values are same, so the final polygon maybe irregular,which is different from the previous post. Note each shape files may have several polygons after merging because the grids with same value are not all in the similar positions. That means i only want to merge those close grids with same value in adjacent positions, and not expect to generate a big polygon with some holes in it.The main problem maybe how to merge those adjacent grids with same values into polygons. #Example data gt <- GridTopology(c(0.05,0.05), c(0.1,0.1), c(10,10)) xv<-rnorm(length(coordinates(gt)[,1])) xvs<-ifelse(xv>0.2,1,0) grd <- SpatialGridDataFrame(gt, data.frame(xvs),proj4string=CRS(as.character(NA))) grdM<-as.matrix(data.frame(coordinates(grd),grd at data)) grdM[1:5,] Any ideas on this? I'd appreciate any suggestions or help. Thanks. -- ----------------- Jane Chang Queen's [[alternative HTML version deleted]] ------------------------------ Message: 12 Date: Tue, 26 Jan 2010 23:26:18 -0500 From: "rusers.sh" <rusers.sh at gmail.com> To: Alexandre Villers <alexandre.villersav at laposte.net> Cc: r-sig-geo at stat.math.ethz.ch Subject: Re: [R-sig-Geo] complement part of a polygon in another polygon Message-ID: <a835c81e1001262026ub45a630v8bad1297a756771b at mail.gmail.com> Content-Type: text/plain intersect.owin() works for intersection. Say polygon B located inside A. Is there any function in R for us to get the complement part of B in polygon A? 2010/1/26 Alexandre Villers <alexandre.villersav at laposte.net> Good morning, You can have a look at union.owin() and intersection.owin() in spatstat. You just need to convert from so objects to spatstat object and back... Best regards Alex -- ----------------- Jane Chang Queen's [[alternative HTML version deleted]] ------------------------------ Message: 13 Date: Tue, 26 Jan 2010 23:06:41 -0900 From: Martin Renner <martin.renner at stonebow.otago.ac.nz> To: r-sig-geo at stat.math.ethz.ch Subject: [R-sig-Geo] kriging as fish swim, not as crows fly Message-ID: <498D5289-7BAA-4D6E-BE6B-F202895BFEF2 at stonebow.otago.ac.nz> Content-Type: text/plain; charset=us-ascii Hi All, I want to kirg fish and seabird densities within an estuary which has several arms. Since neither organisms cross land, the appropriate distances would not be euclidian but over-water (as fish swim). There are several papers, describing this problem and how to deal with it (see below), but I have not found an easily accessible implementation. Is anybody aware of a solution in R? Best, Martin @article{Rathbun:1998aa, Author = {Rathbun, Stephen L.}, Journal = {Environmetrics}, Number = {2}, Pages = {109--129}, Title = {Spatial modelling in irregularly shaped regions: kriging estuaries}, Volume = {9}, Year = {1998}} @article{Little:1997aa, Author = {Little, Laurie S. and Edwards, Don and Porter, Dwayne E.}, Journal = {Journal of Experimental Marine Biology and Ecology}, Number = {1}, Pages = {1--11}, Title = {Kriging in estuaries: as the crow flies, or as the fish swims?}, Volume = {213}, Year = {1997}} Martin Renner US Geological Survey Alaska Science Center ------------------------------ Message: 14 Date: Wed, 27 Jan 2010 10:17:12 +0100 From: Karl Ove Hufthammer <karl at huftis.org> To: r-sig-geo at stat.math.ethz.ch Subject: Re: [R-sig-Geo] Distance to (nearest) polygon Message-ID: <MPG.25ca23071e15ccd89896d4 at news.gmane.org> Content-Type: text/plain; charset="us-ascii" On Tue, 26 Jan 2010 16:27:23 +0100 (CET) Roger Bivand <Roger.Bivand at nhh.no> wrote: For example, I need the distance between points at sea to the nearest land area (as defined by for example the 'world' dataset). There are methods for point to line segment distances in spatstat. Further, for projected (planar) coordinates, this could be added to R-Forge rgeos; for geographical coordinates Boost ggl would be needed. Thanks. The 'nncross' function in 'spatstat' does essentially do what I need. Unfortunately, I work with geographical coordinates (spanning about 15 degrees of latitude), so the results are not perfect (using plain long/lat coordinates), but they will probably be an adequate approximation. BTW, for my application, I'm not interested in the distance per se, only in the points (e.g., boats) within a certain distance from the polygon (land). So I have also thought about a possible solution of using an expanded polygon, expanded in a certain number of kilometers outwards, and then using point-in-polygon (i.e., 'overlay') to find the points that are inside this new polygon. But I couldn't find a function to 'grow' a polygon in this way. -- Karl Ove Hufthammer ------------------------------ Message: 15 Date: Wed, 27 Jan 2010 20:29:15 +1100 From: Michael Sumner <mdsumner at gmail.com> To: Martin Renner <martin.renner at stonebow.otago.ac.nz> Cc: r-sig-geo at stat.math.ethz.ch Subject: Re: [R-sig-Geo] kriging as fish swim, not as crows fly Message-ID: <522664f81001270129g2a80ea2n62e8e6c3442fc7e at mail.gmail.com> Content-Type: text/plain; charset=UTF-8 Not kriging as such, but check out the soap-film smoothing in package mgcv: http://www.maths.bath.ac.uk/~sw283/simon/papers/soap.pdf FWIW, there are binning methods with MCMC in the package tripEstimation that have similar features, but they are particularly focussed on individual track estimation and probably not easily applied. Is location uncertainty a big issue for your data? What are the input locations? Cheers, Mike. On Wed, Jan 27, 2010 at 7:06 PM, Martin Renner <martin.renner at stonebow.otago.ac.nz> wrote: Hi All, I want to kirg fish and seabird densities within an estuary which has several arms. Since neither organisms cross land, the appropriate distances would not be euclidian but over-water (as fish swim). There are several papers, describing this problem and how to deal with it (see below), but I have not found an easily accessible implementation. Is anybody aware of a solution in R? Best, Martin @article{Rathbun:1998aa, ? ? ? ?Author = {Rathbun, Stephen L.}, ? ? ? ?Journal = {Environmetrics}, ? ? ? ?Number = {2}, ? ? ? ?Pages = {109--129}, ? ? ? ?Title = {Spatial modelling in irregularly shaped regions: kriging estuaries}, ? ? ? ?Volume = {9}, ? ? ? ?Year = {1998}} @article{Little:1997aa, ? ? ? ?Author = {Little, Laurie S. and Edwards, Don and Porter, Dwayne E.}, ? ? ? ?Journal = {Journal of Experimental Marine Biology and Ecology}, ? ? ? ?Number = {1}, ? ? ? ?Pages = {1--11}, ? ? ? ?Title = {Kriging in estuaries: as the crow flies, or as the fish swims?}, ? ? ? ?Volume = {213}, ? ? ? ?Year = {1997}} Martin Renner US Geological Survey Alaska Science Center _______________________________________________ R-sig-Geo mailing list R-sig-Geo at stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo ------------------------------ _______________________________________________ R-sig-Geo mailing list R-sig-Geo at stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo End of R-sig-Geo Digest, Vol 77, Issue 24 *****************************************
-- With Kind Regards, oooO::::::::: (..)::::::::: :\.(:::Oooo:: ::\_)::(..):: :::::::)./::: ::::::(_/:::: ::::::::::::: [***********************************************************************] ZhiJie Zhang ,PhD Dept.of Epidemiology, School of Public Health,Fudan University Office:Room 443, Building 8 Office Tel./Fax.:+86-21-54237410 Address:No. 138 Yi Xue Yuan Road,Shanghai,China Postcode:200032 Email:epistat at gmail.com <Email%3Aepistat at gmail.com> Website: www.statABC.com [***********************************************************************] oooO::::::::: (..)::::::::: :\.(:::Oooo:: ::\_)::(..):: :::::::)./::: ::::::(_/:::: :::::::::::::
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.Bivand at nhh.no