[R-sig-Geo] raster package - zonal - standard deviations

[Christian Levers]

Hi Rafael,

thanks for the quick reply. I'm using version 2.0-12, on a Win7 platform 
though. Since your little code works also fine for me, I guess its a 
matter of my input raster(s). Here is the printout:

 > relnrg_mskd <- zonal(slope_final_mskd.tif, zone.raster, 'sd')
Fehler in .local(x, z, ...) : stat can be 'sum', 'mean', 'min', or 'max'

für:
 > slope_final_mskd.tif
class       : RasterLayer
dimensions  : 5320, 6270, 33356400  (nrow, ncol, ncell)
resolution  : 1000, 1000  (x, y)
extent      : 1500000, 7770000, 740000, 6060000 (xmin, xmax, ymin, ymax)
coord. ref. : +proj=laea +lat_0=52 +lon_0=10 +x_0=4321000 +y_0=3210000 
+ellps=GRS80 +units=m +no_defs
names       : slope_final_mskd
values      : 0, 46  (min, max)

 > zone.raster
class       : RasterLayer
dimensions  : 5320, 6270, 33356400  (nrow, ncol, ncell)
resolution  : 1000, 1000  (x, y)
extent      : 1500000, 7770000, 740000, 6060000 (xmin, xmax, ymin, ymax)
coord. ref. : +proj=laea +lat_0=52 +lon_0=10 +x_0=4321000 +y_0=3210000 
+ellps=GRS80 +units=m +no_defs
names       : harvestmap_efi
values      : 1, 460  (min, max)

Cheers,
Christian

Am 05.11.2012 16:35, schrieb Rafael Wüest:
> Hi Christian
>
> What version of raster do you use. Using my installation of raster (version 2.0-12), 'sd' as a function in zonal works fine (see example below).
>
> r <- raster(ncols=10, nrows=10)
> r[] <- runif(ncell(r)) * 1:ncell(r)
> z <- r
> z[] <- rep(1:5, each=20)
> zonal(r, z, 'sd')
>       zone      "sd"
> [1,]    1  4.894058
> [2,]    2  9.216353
> [3,]    3 14.144341
> [4,]    4 19.973913
> [5,]    5 27.934773
>
> I guess updating the raster package will solve the problem.
>
> Best,
> Rafael
>
> On 02.11.2012, at 18:35, Christian Levers wrote:
>
>> Hello,
>>
>> I am using the raster package to calculate zonal statistics for my stack of ca. 50 rasters (each raster is about 33 mio. pixels) and I am wondering if there is a simple way to calculate standard deviations for the zones since "sd" is not implemented in the presets for the "stat" argument. If not, I guess defining a function which calculates std.dev is the easiest solution.
>>
>> Thanks in advance and a nice weekend,
>> Christian
>>
>> --
>> MSc Geogr. Christian Levers
>> Doctoral Researcher
>>
>> Biogeography & Conservation Biology
>> Geography Department | Humboldt-Universitaet zu Berlin
>>
>> eMail:  christian.levers at geo.hu-berlin.de
>> phone:  +49 (0) 30 2093 9341
>> fax:    +49 (0) 30 2093 6848
>> mail:   Unter den Linden 6 | 10099 Berlin | Germany
>> web:    http://www.geographie.hu-berlin.de
>>
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>
>
>
> --
> Rafael Wüest
> Swiss Federal Research Institute WSL
> Zürcherstrasse 111
> 8903 Birmensdorf
> Switzerland
>
> +41 44 7392126
> rafael.wueest at wsl.ch
> http://www.wsl.ch/info/mitarbeitende/wueest/index_EN
>
>
>


-- 
MSc Geogr. Christian Levers
Doctoral Researcher

Biogeography & Conservation Biology
Geography Department | Humboldt-Universitaet zu Berlin

eMail:  christian.levers at geo.hu-berlin.de
phone:  +49 (0) 30 2093 9341
fax:    +49 (0) 30 2093 6848
mail:   Unter den Linden 6 | 10099 Berlin | Germany
web:    http://www.geographie.hu-berlin.de