Ideas on qualifying urban shapes: linear / circular / star

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Ideas on qualifying urban shapes: linear / circular / star

 Hello list, I have determined major urban areas. This is just a post to get ideas from R-users on how to qualify urban shapes. The data can either be binary raster (urban/ not urban), either vector. 1) Some urban areas follow linear infrastructures, thus are linear 2) Some other diverge equally from a central heart, and are circular. 3) Some are a mix and are like stars. The idea would be to get an index that give for each area, the probability of belonging to each of these three classes. Like a 3-column data frame I wondered if packages already existed, or statistical methods for this purpose. Notably, I think that topographic derivatives derived from smoothed/unsmoothed binary data like aspect, could be used to qualify these shapes (?) Thanks for any idea or exchange on the subject! Mathieu         [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list [hidden email] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
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Re: Ideas on qualifying urban shapes: linear / circular / star

 On Fri, Sep 30, 2011 at 10:21 AM, Mathieu Rajerison <[hidden email]> wrote: > Hello list, > > > I have determined major urban areas. > > This is just a post to get ideas from R-users on how to qualify urban > shapes. > > The data can either be binary raster (urban/ not urban), either vector. > > 1) Some urban areas follow linear infrastructures, thus are linear > 2) Some other diverge equally from a central heart, and are circular. > 3) Some are a mix and are like stars. > > The idea would be to get an index that give for each area, the probability > of belonging to each of these three classes. Like a 3-column data frame > > I wondered if packages already existed, or statistical methods for this > purpose. Notably, I think that topographic derivatives derived from > smoothed/unsmoothed binary data like aspect, could be used to qualify these > shapes (?) > > Thanks for any idea or exchange on the subject!  Sounds like shape analysis or morphometrics. There's package:shape that might help. Sometimes these techniques depend on landmarks though (like the locations of eyes, noses, and ears on faces) and probably won't be any use on vector or raster datasets. http://en.wikipedia.org/wiki/MorphometricsBarry _______________________________________________ R-sig-Geo mailing list [hidden email] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
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Re: Ideas on qualifying urban shapes: linear / circular / star

 In reply to this post by Mathieu Rajerison Hi, On Fri, Sep 30, 2011 at 5:21 AM, Mathieu Rajerison <[hidden email]> wrote: > Hello list, > > > I have determined major urban areas. > > This is just a post to get ideas from R-users on how to qualify urban > shapes. > > The data can either be binary raster (urban/ not urban), either vector. > > 1) Some urban areas follow linear infrastructures, thus are linear > 2) Some other diverge equally from a central heart, and are circular. > 3) Some are a mix and are like stars. That sounds like the kind of task that patch metrics such as perimeter/area ratio and fractal dimension were created for. Take a look at the copious Fragstats literature. I don't know if any have been implemented in R, but wouldn't be surprised. Sarah > The idea would be to get an index that give for each area, the probability > of belonging to each of these three classes. Like a 3-column data frame > > I wondered if packages already existed, or statistical methods for this > purpose. Notably, I think that topographic derivatives derived from > smoothed/unsmoothed binary data like aspect, could be used to qualify these > shapes (?) > > Thanks for any idea or exchange on the subject! > -- Sarah Goslee http://www.functionaldiversity.org_______________________________________________ R-sig-Geo mailing list [hidden email] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
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Re: Ideas on qualifying urban shapes: linear / circular / star

 Hi, Maybe you're right: perimeter/ratio could be sufficient... Fractal dimension and lacunarity are good indicators for urban areas. Do you know any R package, tool to quantify these? I have found an ImageJ plugin called Fraclac. There is another one called r.lacunarity included in spatialtools http://www.clusterville.org/spatialtools/index.htmlr.lacunarity is interesting compared to ImageJ::Fraclac because it uses a moving window and generates a raster. I launched a post about lacunarity and fractal dimension on R but didn't have any answer. So, if anyone manages to use r.lacunarity or knows other tools than Fraclac, I'd be happy! For those interested , here is some literature on fractal dimension applied to analysis or aerial images or cities: http://www.public.asu.edu/~smyint/publications/CEUS-Lacunarity-Myint-Lam.pdfhttp://cybergeo.revues.org/8902http://www.isprs.org/proceedings/XXXVII/congress/3b_pdf/80.pdfhttp://www.fatih.edu.tr/~mcadams/geo352/fractal.pdf2011/9/30 Sarah Goslee <[hidden email]> > Hi, > > On Fri, Sep 30, 2011 at 5:21 AM, Mathieu Rajerison > <[hidden email]> wrote: > > Hello list, > > > > > > I have determined major urban areas. > > > > This is just a post to get ideas from R-users on how to qualify urban > > shapes. > > > > The data can either be binary raster (urban/ not urban), either vector. > > > > 1) Some urban areas follow linear infrastructures, thus are linear > > 2) Some other diverge equally from a central heart, and are circular. > > 3) Some are a mix and are like stars. > > That sounds like the kind of task that patch metrics such as perimeter/area > ratio and fractal dimension were created for. Take a look at the copious > Fragstats literature. I don't know if any have been implemented in R, but > wouldn't be surprised. > > Sarah > > > The idea would be to get an index that give for each area, the > probability > > of belonging to each of these three classes. Like a 3-column data frame > > > > I wondered if packages already existed, or statistical methods for this > > purpose. Notably, I think that topographic derivatives derived from > > smoothed/unsmoothed binary data like aspect, could be used to qualify > these > > shapes (?) > > > > Thanks for any idea or exchange on the subject! > > > > > -- > Sarah Goslee > http://www.functionaldiversity.org>         [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list [hidden email] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
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Re: Ideas on qualifying urban shapes: linear / circular / star

 Mathieu, On Fri, Sep 30, 2011 at 9:24 AM, Mathieu Rajerison <[hidden email]> wrote: > Hi, > > > Maybe you're right: perimeter/ratio could be sufficient... > > Fractal dimension and lacunarity are good indicators for urban areas. Do you > know any R package, tool to quantify these? I've always just used Fragstats, as I already suggested, but you might look into SDMtools: http://cran.r-project.org/web/packages/SDMTools/http://mo-seph.com/node/302Sarah > I have found an ImageJ plugin called Fraclac. > > There is another one called r.lacunarity included in spatialtools > http://www.clusterville.org/spatialtools/index.html> r.lacunarity is interesting compared to ImageJ::Fraclac because it uses a > moving window and generates a raster. > > I launched a post about lacunarity and fractal dimension on R but didn't > have any answer. > > > So, if anyone manages to use r.lacunarity or knows other tools than Fraclac, > I'd be happy! > > > For those interested , here is some literature on fractal dimension applied > to analysis or aerial images or cities: > http://www.public.asu.edu/~smyint/publications/CEUS-Lacunarity-Myint-Lam.pdf> http://cybergeo.revues.org/8902> http://www.isprs.org/proceedings/XXXVII/congress/3b_pdf/80.pdf> http://www.fatih.edu.tr/~mcadams/geo352/fractal.pdf> > > 2011/9/30 Sarah Goslee <[hidden email]> >> >> Hi, >> >> On Fri, Sep 30, 2011 at 5:21 AM, Mathieu Rajerison >> <[hidden email]> wrote: >> > Hello list, >> > >> > >> > I have determined major urban areas. >> > >> > This is just a post to get ideas from R-users on how to qualify urban >> > shapes. >> > >> > The data can either be binary raster (urban/ not urban), either vector. >> > >> > 1) Some urban areas follow linear infrastructures, thus are linear >> > 2) Some other diverge equally from a central heart, and are circular. >> > 3) Some are a mix and are like stars. >> >> That sounds like the kind of task that patch metrics such as >> perimeter/area >> ratio and fractal dimension were created for. Take a look at the copious >> Fragstats literature. I don't know if any have been implemented in R, but >> wouldn't be surprised. >> >> Sarah >> >> > The idea would be to get an index that give for each area, the >> > probability >> > of belonging to each of these three classes. Like a 3-column data frame >> > >> > I wondered if packages already existed, or statistical methods for this >> > purpose. Notably, I think that topographic derivatives derived from >> > smoothed/unsmoothed binary data like aspect, could be used to qualify >> > these >> > shapes (?) >> > >> > Thanks for any idea or exchange on the subject! >> > >> >> -- Sarah Goslee http://www.functionaldiversity.org_______________________________________________ R-sig-Geo mailing list [hidden email] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
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Re: Ideas on qualifying urban shapes: linear / circular / star

 In reply to this post by Mathieu Rajerison Hi, Sarah's idea with FRAGSTATS isn't a bad one. I gather that you would like to do it in R. FRAGTSTATS can be used from the command line and anything that can be accessed with the command line is game for R. A quick look at the FRAGSTATS manual will tell you that you need to create  a parameterization file in FRAGSTATS. Then: system("/Drive:/path_to_Fragstats/Fragstats path_to_file/file.asc ParameterizationFile.frg///c/") I hope, I didn't duplicate anything in answering later... Cheers, Brian         [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list [hidden email] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
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Re: Ideas on qualifying urban shapes: linear / circular / star

 Hi, Thanks all for the answers. I'll take a look at FRAGSTATS software. It looks very interesting. Mathieu 2011/10/1 Brian Oney <[hidden email]> > ** > Hi, > Sarah's idea with FRAGSTATS isn't a bad one. I gather that you would like > to do it in R. > FRAGTSTATS can be used from the command line and anything that can be > accessed with the command line is game for R. > A quick look at the FRAGSTATS manual will tell you that you need to create > a parameterization file in FRAGSTATS. Then: > > system("*Drive:/path_to_Fragstats/Fragstats path_to_file/file.asc > ParameterizationFile.frg** /c*") > > I hope, I didn't duplicate anything in answering later... > > Cheers, > Brian >         [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list [hidden email] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
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Re: Ideas on qualifying urban shapes: linear / circular / star

 For those interested, FRAGSTATS seems to totally answer my issue. Thanks for making me discover it. It allows calculation of shape metrics. http://www.umass.edu/landeco/research/fragstats/documents/Metrics/Shape%20Metrics/SHAPE%20METRICS.htmI'm not an R developper but I do think it would deserve an R package or at least an implementation in an existing one :) 2011/10/3 Mathieu Rajerison <[hidden email]> > Hi, > > Thanks all for the answers. I'll take a look at FRAGSTATS software. It > looks very interesting. > > Mathieu > > > 2011/10/1 Brian Oney <[hidden email]> > >> ** >> Hi, >> Sarah's idea with FRAGSTATS isn't a bad one. I gather that you would like >> to do it in R. >> FRAGTSTATS can be used from the command line and anything that can be >> accessed with the command line is game for R. >> A quick look at the FRAGSTATS manual will tell you that you need to >> create  a parameterization file in FRAGSTATS. Then: >> >> system("*Drive:/path_to_Fragstats/Fragstats path_to_file/file.asc >> ParameterizationFile.frg** /c*") >> >> I hope, I didn't duplicate anything in answering later... >> >> Cheers, >> Brian >> > >         [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list [hidden email] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
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Re: Ideas on qualifying urban shapes: linear / circular / star

 On Mon, Oct 3, 2011 at 10:47 AM, Mathieu Rajerison <[hidden email]> wrote: > I'm not an R developper but I do think it would deserve an R package or at > least an implementation in an existing one :)  It seems to be only available as a Windows binary download with a Public Domain license. Step 1 would be asking the authors to publish their source code under an open source license. Then we can talk about R packges! Barry _______________________________________________ R-sig-Geo mailing list [hidden email] https://stat.ethz.ch/mailman/listinfo/r-sig-geo