[R-sig-Geo] From Spatial Points Data Frame to Spatial Polygons Data Frame

[Agustin Lobo]

Thanks, works perfectly!
Much better through SpatialPixelsDataFrame than through grid.
This is also simplifying another script.
Agus

On Thu, Jan 23, 2014 at 3:03 PM, Edzer Pebesma
<edzer.pebesma at uni-muenster.de> wrote:
> try:
>
> x = as(SpatialPixelsDataFrame(tmetad1, tmetad1 at data, tolerance=.00086),
>         "SpatialPolygonsDataFrame")
> spplot(x[2])
>
> On 01/23/2014 02:06 PM, Agustin Lobo wrote:
>> Hi!
>>
>> I'm trying to convert an SPointsDF of a set of points
>> distributed as the centers of the cells of a 4x5 grid
>> into a SPolygonsDF
>> This is because the data actually come from the cell and not
>> just from its center, and want to be able to export as shape and display the
>> polygon grid on top of other information. The central points
>> are not sufficient.
>>
>> The way I'm doing it is not good because I lose the slot data
>> of the SPointsDF. I can attach the data to the polygons afterwards, but
>> the original points follow a weird order and I'm concerned about
>> not attaching the data in the correct order.
>> Hopefully somebody can suggest an alternative way that would keep
>> the data slot.
>>
>> What I do is:
>>
>> load("https://dl.dropboxusercontent.com/u/3180464/tmetad1.rda")
>> tmetadg  <- points2grid(tmetad1,tolerance=0.000856898)
>> tmetadg2  <- SpatialGrid(tmetadg, proj4string=CRS("+init=epsg:4326"))
>> tmetadpol <- as(tmetadg2, "SpatialPolygons")
>>
>> I can try with:
>> tmetadpolDF <- SpatialPolygonsDataFrame(tmetadpol,data=tmetad1 at data,match.ID=FALSE)
>>
>> but the data actually get in a wrong order (by rows instead of by columns).
>> The row.names of tmetad1 at coords are not saved in tmetadg, so do not
>> see how I could
>> use match.ID.
>>
>> Thanks
>>
>> Agus
>>
>> _______________________________________________
>> R-sig-Geo mailing list
>> R-sig-Geo at r-project.org
>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>
>
> --
> Edzer Pebesma
> Institute for Geoinformatics (ifgi), University of Münster
> Heisenbergstraße 2, 48149 Münster, Germany. Phone: +49 251
> 83 33081 http://ifgi.uni-muenster.de GPG key ID 0xAC227795
>
>
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo at r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>