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## units for spatial range in stvariogram gstat

Dear All,
I have question concerning the unit of measurement for the range parameter in the fit.stvariogram in gstat, i have fitted the following spatio temporal variogram for data on monthly averages pf pm10 and the longitude and latitude are in decimel format

> pm10_sp
SpatialPoints:
longitude latitude
1     30.92500 29.95300
61    31.36000 30.26000
121   31.33300 29.84720
and this is the commands for fitting the variogram
> varpm10 <- variogramST(lnpm10only~1,data=lnpm10_stfdf,cutoff=0.8,assumeRegular=T,na.omit=T)
> plot(varpm10,map=F)
> sumMetric <- vgmST("sumMetric", space = vgm(psill=5,"Mat", range=50, nugget=0),time = vgm(psill=500,"Mat", range=50, nugget=0,kappa=0.3), joint = vgm(psill=10,"Mat", range=100, nugget=1), stAni=200)
> sumMetric_Vgm <- fit.StVariogram(varpm10, sumMetric, method="L-BFGS-B",lower=pars.l,upper=pars.u)
> plot(varpm10,sumMetric_Vgm,map=F)

> extractPar(sumMetric_Vgm)
sill.s      range.s     nugget.s       sill.t      range.t     nugget.t
1.73598444  50.63845035   0.03212857   0.01570379  49.99811448   0.00000000
sill.st     range.st    nugget.st         anis
0.00000000 100.00004052   0.09151787 200.00000000

--
now i want to know the units for these parameters in order to be able to interpret it for example is it in km or m.

I really appreciate any help that I deeply need

Best Regards
Sara Faculty of Economics & Political ScienceCairo University

Tel:(202)35728055-(202)35728116-(202)35736608-(202)35736605
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## Re: units for spatial range in stvariogram gstat

 Your email is not nearly enough for a reader to figure out what you did. However, if your data are long/lat, and you instructed gstat about that (i.e., proj4string(pm10_sp) indicates coordinates are degrees) then gstat computes and returns distances in km. On 17/05/17 20:56, sara osama wrote: > > Dear All, > I have question concerning the unit of measurement for the range > parameter in the fit.stvariogram in gstat, i have fitted the following > spatio temporal variogram for data on monthly averages pf pm10 and the > longitude and latitude are in decimel format >   >> pm10_sp > SpatialPoints: >      longitude latitude > 1     30.92500 29.95300 > 61    31.36000 30.26000 > 121   31.33300 29.84720 >  and this is the commands for fitting the variogram >> varpm10 <- variogramST(lnpm10only~1,data=lnpm10_stfdf,cutoff=0.8,assumeRegular=T,na.omit=T) >> plot(varpm10,map=F) >> sumMetric <- vgmST("sumMetric", space = vgm(psill=5,"Mat", range=50, nugget=0),time = vgm(psill=500,"Mat", range=50, nugget=0,kappa=0.3), joint = vgm(psill=10,"Mat", range=100, nugget=1), stAni=200) >> sumMetric_Vgm <- fit.StVariogram(varpm10, sumMetric, method="L-BFGS-B",lower=pars.l,upper=pars.u) >> plot(varpm10,sumMetric_Vgm,map=F) >   >> extractPar(sumMetric_Vgm) >       sill.s      range.s     nugget.s       sill.t      range.t     > nugget.t >   1.73598444  50.63845035   0.03212857   0.01570379  49.99811448   > 0.00000000 >      sill.st     range.st   > nugget.st         anis >   0.00000000 100.00004052   0.09151787 200.00000000 >   > -- > now i want to know the units for these parameters in order to be able to > interpret it for example is it in km or m. >   > I really appreciate any help that I deeply need >   > Best Regards > Sara > > Faculty of Economics & Political Science > Cairo University > > > Tel:(202)35728055-(202)35728116-(202)35736608-(202)35736605 > Fax:(202)35711020 > Follow us on twitter:https://twitter.com/fepsnews> > > _______________________________________________ > R-sig-Geo mailing list > [hidden email] > https://stat.ethz.ch/mailman/listinfo/r-sig-geo> -- Edzer Pebesma Institute for Geoinformatics  (ifgi),  University of Münster Heisenbergstraße 2, 48149 Münster, Germany; +49 251 83 33081 Journal of Statistical Software:   http://www.jstatsoft.org/Computers & Geosciences:   http://elsevier.com/locate/cageo/_______________________________________________ R-sig-Geo mailing list [hidden email] https://stat.ethz.ch/mailman/listinfo/r-sig-geo signature.asc (484 bytes) Download Attachment
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## Re: units for spatial range in stvariogram gstat

 Dear Prof. Pebesma, Thanks for reply I will try to make it  more clear the coordinates are converted to decimal degree format using the equation DD = d + (min/60) + (sec/3600) and then projected using > llCRS <- CRS("+proj=longlat +ellps=WGS84") > pm10_sp <- SpatialPoints(coords, proj4string = llCRS) > pm10_sp SpatialPoints:      longitude latitude 1     30.92500 29.95300 61    31.36000 30.26000  and the variogram is fitted using >> varpm10 <- variogramST(lnpm10only~1,data=lnpm10_stfdf,cutoff=0.8, assumeRegular=T,na.omit=T) >> sumMetric <- vgmST("sumMetric", space = vgm(psill=5,"Mat", range=50, nugget=0),time = vgm(psill=500,"Mat", range=50, nugget=0,kappa=0.3), joint = vgm(psill=10,"Mat", range=100, nugget=1), stAni=200) >> sumMetric_Vgm <- fit.StVariogram(varpm10, sumMetric, method="L-BFGS-B",lower=pars.l,upper=pars.u) *the s.range parameter extracted was 50.6 but if you take a look on  the figure attached the largest distance on the x-axis is 0.6 ??????* *so i think the unit on the figure is not the unit of the extracted parameter. * by the way the largest ditance between any points in my data set is approximately 190 km Thanks again On Wed, May 17, 2017 at 10:08 PM, Edzer Pebesma < [hidden email]> wrote: > Your email is not nearly enough for a reader to figure out what you did. > However, if your data are long/lat, and you instructed gstat about that > (i.e., proj4string(pm10_sp) indicates coordinates are degrees) then > gstat computes and returns distances in km. > > On 17/05/17 20:56, sara osama wrote: > > > > Dear All, > > I have question concerning the unit of measurement for the range > > parameter in the fit.stvariogram in gstat, i have fitted the following > > spatio temporal variogram for data on monthly averages pf pm10 and the > > longitude and latitude are in decimel format > > > >> pm10_sp > > SpatialPoints: > >      longitude latitude > > 1     30.92500 29.95300 > > 61    31.36000 30.26000 > > 121   31.33300 29.84720 > >  and this is the commands for fitting the variogram > >> varpm10 <- variogramST(lnpm10only~1,data=lnpm10_stfdf,cutoff=0.8, > assumeRegular=T,na.omit=T) > >> plot(varpm10,map=F) > >> sumMetric <- vgmST("sumMetric", space = vgm(psill=5,"Mat", range=50, > nugget=0),time = vgm(psill=500,"Mat", range=50, nugget=0,kappa=0.3), joint > = vgm(psill=10,"Mat", range=100, nugget=1), stAni=200) > >> sumMetric_Vgm <- fit.StVariogram(varpm10, sumMetric, > method="L-BFGS-B",lower=pars.l,upper=pars.u) > >> plot(varpm10,sumMetric_Vgm,map=F) > > > >> extractPar(sumMetric_Vgm) > >       sill.s      range.s     nugget.s       sill.t      range.t > > nugget.t > >   1.73598444  50.63845035   0.03212857   0.01570379  49.99811448 > > 0.00000000 > >      sill.st     range.st > > nugget.st         anis > >   0.00000000 100.00004052   0.09151787 200.00000000 > > > > -- > > now i want to know the units for these parameters in order to be able to > > interpret it for example is it in km or m. > > > > I really appreciate any help that I deeply need > > > > Best Regards > > Sara > > > >       Faculty of Economics & Political Science > > Cairo University > > > > > > Tel:(202)35728055-(202)35728116-(202)35736608-(202)35736605 > > Fax:(202)35711020 > > Follow us on twitter:https://twitter.com/fepsnews> > > > > > _______________________________________________ > > R-sig-Geo mailing list > > [hidden email] > > https://stat.ethz.ch/mailman/listinfo/r-sig-geo> > > > -- > Edzer Pebesma > Institute for Geoinformatics  (ifgi),  University of Münster > Heisenbergstraße 2, 48149 Münster, Germany; +49 251 83 33081 > Journal of Statistical Software:   http://www.jstatsoft.org/> Computers & Geosciences:   http://elsevier.com/locate/cageo/> > > _______________________________________________ > R-sig-Geo mailing list > [hidden email] > https://stat.ethz.ch/mailman/listinfo/r-sig-geo> -- Best Regards Faculty of Economics & Political Science Cairo University Tel:(202)35728055-(202)35728116-(202)35736608-(202)35736605 Fax:(202)35711020 Follow us on twitter:https://twitter.com/fepsnews        [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list [hidden email] https://stat.ethz.ch/mailman/listinfo/r-sig-geo